Ocenite etot tekst:





Dannyj FAQ sostavlen po materialam FIDO-konferencii RU.CISCO,
newsgroup comp.dcom.sys.cisco, spiska rassylki inet-admins
i drugih istochnikov.

Spasibo vsem obitatelyam ehi RU.CISCO.
Spasibo vsem, kto prisylal ssylki, pary q/a.

Pytayushchijsya inogda vesti FAQ - Dmitriy Yermakov, dyer@sut.ru, 2:5030/1115
Data poslednej modifikacii - 17 yanvarya 2001.

Dopolneniya, ispravleniya luchshe prisylat' na dyer@sut.ru

http://cube.sut.ru/~dyer/faq/cisco.html
Tekstovaya versiya
ftp://ftp.east.ru/pub/inet-admins/cisco.txt


DISCLAIMER.
Sostavitel' dannogo teksta ne yavlyaetsya Cisco-guru
i ne osushchestvlyaet tech-support by e-mail or netmail.

0. Obshchie voprosy
1. Sync,Async,AUX,Callback
2. FR
3. X25
4. ACL
5. Traffic-shape
6. Routing
7. TACACS,RADIUS,AAA
8. Memory
9. NTP, TZ
10. NAT
11. Telco, ISDN

13. SNMP
14. Cables
15. TROUBLESHOOTING
97. Software
98. IOS Black Lis/White List/Recommendations
99. Misc
Zametki na polyah

===========================================================

0. Obshchie voprosy

=========================================================== 0.1>Q: Gde mozhno chto-to pochitat' pro Cisco ? >A: horom :) UniverCD, idushchij v postavke. http://www.cisco.com i http://www-europe.cisco.com [11.09.2000] Po povodu UniverCD. A>:(Dmitry Morozovsky) 'Novye' DocCD ot Cisco - gzip-compressed ------- httpd.conf: Action text/gzipped /cgi-bin/gzcat.cgi? AddHandler text/gzipped .html .htm ------- gzcat.cgi: #!/bin/sh - echo "Content-type: text/html" echo "" HF=${DOCUMENT_ROOT}/$REQUEST_URI if [ -r $HF ]; then gzcat -f $HF else echo "No such file, sorry" fi >A: Po povodu ustanovki pod Win2k (Sergey Zarubin) From: "Evan Wagner" Newsgroups: comp.dcom.sys.cisco Subject: Re: Windows 2000 & Cisco CD Date: Thu, 20 Apr 2000 23:04:18 -0400 To get the Cisco documentation to work under Windows 2000: Run regedit Export your registry (as a precaution) Locate the Windows 2000 Registry Key: HKEY_LOCAL_MACHINE/SOFTWARE/Microsoft/IE4/Setup/Path Change the value from "%programfiles%\Internet Explorer" to the location where IE is installed on your system, for example "D:\Program Files\Internet Explorer" Uninstall the Cisco Documentation CD Delete the old install directory Reinstall the Cisco documentation CD and you should be good to go. >A: Aleksandr Rainchik Cisco Systems and Cisco Routers in a Nutshell http://www.clark.net/pub/rbenn/cisco.html Est' takoj zamechatel'nyj server: McGraw-Hill Beta Books http://www.pbg.mcgraw-hill.com/betabooks/betabooks-home.html >A: (Dmitriy Yermakov) Koe-kakie konkretnye primery konfigov est' na Relkome http://relcom.eu.net/INFO/NOC-IP/FAQ/faq.html DEOle http://www.deol.ru/~bog/work/cisco_access.html Sample Configurations na www.cisco.com http://www.cisco.com/warp/public/700/tech_configs.html Guide to Cisco Router Configuration http://www.primenet.com/~web/router/cisco-configuration.html Cisco routery i bor'ba s nimi v bibliotete M.Moshkova http://www.parkline.ru/Library/koi/CISCO/ TACACS-FAQ - http://www.easynet.de/tacacs-faq Spisok AV-pairs dlya TACACS - http://www.cisco.com/univercd/cc/td/doc/product/access/acs_soft/csacs4nt/csnt23/csnt23ug/ap_tacac.htm CISCO-FAQ - comp.dcom.sys.cisco Frequently Asked Questions http://cube.sut.ru/~dyer/faq/cisco-networking-faq.txt i ftp://ftp.east.ru/pub/inet-admins/cisco-networking-faq.txt CISCO-FAQ na servere Cisco - http://www.cisco.com/warp/public/458/index.shtml Arhiv mailing-list inet-admins http://info.east.ru/win/inetadm.html gde tozhe est' voprosy/otvety. I ne tol'ko po Cisco. Nebol'shoj FAQ http://www.sunshine.dp.ua/os/reports/ciscofaq.html Stat'i s soobshcheniyami iz RU.CISCO na http://www.opennet.ru/base/cisco [07.09.2000] >A: Martin McFlySr Poisk po kiske na dvizhke Google http://cisco.google.com/cisco [18.09.2000] Obzor literatury Cisco Press "S.Zaytsev" 0.2>Q: Gde vzyat' arhiv RU.CISCO ? >A: (Dmitriy Yermakov) http://www.dejanews.com :) 0.3>Q: Gde vzyat' svezhij IOS ? >A: (Denis Saveliev) Beta versii lezhat na ftp://ftpeng.cisco.com/isp P.S. (DY) Voobshchem-to IOS ne besplaten. [13.06.2000] 0.4>Q: CHto takoe NetFlow i s chem ego edyat ? >A: (DY) Podrobnee ob etom mozhno pochitat' na Cisco http://www.cisco.com/warp/public/732/netflow Programmy dlya sborki i obrabotki statistiki NetFlow. http://www.auckland.ac.nz/net/NeTraMet http://www.caida.org/Tools/Cflowd Na etih zhe sajtah est' eshche ssylki, no eti - kazhetsya samye populyarnye. Est' eshche http://www.ipmeter.com (billing) nuzhen NeTraMet. [05.09.2000]I eshche ssylochka http://www.switch.ch/tf-tant/floma/software.html#netflow >A: (Vladislav Nebolsine) Primery konfiguracii - http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/120newft/120t/120t3/policyrt.htm tam zhe ssylki na dopolnitel'nuyu dokumentaciyu. ===========================================================

1. Sync,Async,AUX,Callback

=========================================================== 1.1>Q: Podskazhite kak na Cisco 2509 sdelat' vhod s modemov na IFCICO ! >A: (Dmitriy Yermakov) Pri ispol'zovanii TACACS sm. nizhe. username **EMSI_INQC816 nopassword username **EMSI_INQC816 autocommand telnet [host] [port_ifcico] /stream neobhobimost' nalichiya klyuchika /stream luchshe proverit' opytnym putem po povodu banner login # **EMSI_REQA77E # nado/ne nado k okonchatel'nomu resheniyu ne prishli u menya eto est' >A: (Alecsey Gusev) username **EMSI_INQC816 nopassword noescape username **EMSI_INQC816 autocommand telnet username **EMSI_INQC816**EMSI_INQC816q. nopassword noescape username **EMSI_INQC816**EMSI_INQC816q. autocommand telnet username **EMSI_INQC816q nopassword noescape username **EMSI_INQC816q autocommand telnet username **EMSI_TZP16B2 nopassword noescape username **EMSI_TZP16B2 autocommand telnet ne nuzhen banner login # **EMSI_REQA77E # >A: (Alecsey Gusev) Dlya Argus'a nado dobavit' pol'zovatelya **EMSI_TZP16B2, argus pervym delom posylaet eto. [19.07.2000] (Sergei Shumakov) takogo argus tochno ne delaet. vot eto -TZP16B2- on poslat' mozhet, no tol'ko posle togo, kak pojmal **EMSI_REQA77E. >A: patchik dlya ifcico (Maksim Malchuk) *** session.c.orig Wed Dec 27 16:22:31 1995 - --- session.c Tue Feb 13 08:48:13 1996 *************** *** 163,168 **** - --- 163,170 ---- SM_ERROR; } + PUTSTR("**EMSI_INQC816\r"); + p=buf; /*PUTSTR(" \r");*/ PUTCHAR('\r'); 1.2>Q: Dialout service for unix ili kak pricepit' port NAS'a k chemu nibud'. >A: Alex Tutubalin, Vadim Mikhailov Win95/NT http://www.cisco.com - dialout serice ili kak tam ego. FreeBSD,Linux modemu-0.0.1 |muliruet /dev/ttyXX cherez lyuboj telnet. Dlya ciski eto budet inversnyj telnet na port 2000+n. Ho faksy vryad li cherez eto poshlesh', hotya kto ego znaet? (AT): Ha 2000+n poptu net flow control. A dialout hodit na 6000+n. nettty - gde-to v rajone http://www.livingston.com >A: (Leonid Kirillov) Pod Win'95/3.x/NT problema reshaetsya pri pomoshchi http://www.cisco.com/univercd/cc/td/doc/product/access/dialout/index.htm. Sposob resheniya problemy pod DOSom neizvesten. 1.3>Q: Mozhno-li kak-nibud' organizovat' popadanie ne na opredelennuyu liniyu, a na pervuyu svobodnuyu, skazhem? Mne dumaetsya, chto eto mozhno kak-to organizovat' cherez ob容dinenie mozhet, v Dialer Group? Voobshche, interesno;) >A: (Vasily Ivanov) 5000+nomer chepez ustanovlenyj rotary na nuzhnyh liniyah. 1.4>Q: Hotelos' nemnogogo - pricepit' modem na AUX. Propisal emu sleduyushchee: line aux 0 location TESTING access-class 1 in password line anything script reset reset-modem modem InOut transport preferred none transport input all transport output none stopbits 1 rxspeed 19200 txspeed 19200 flowcontrol hardware Zajdya telnetom na etot modem, naruzhu pozonit' ya mogu, a zvonyu na nego snaruzhi - tishina, modem podnimaet trubku i molchit, posle chego otvalivaet. Hikakih promptov, nichego. Ostal'nye vosem' modemov rabotayut normal'no. Kuda mne pnut' kisku, chtoby ona priznala AUX? IOS 11.2. >A: (Sergey Zhuk) line aux 0 login local modem Dialin terminal-type vt100 stopbits 1 rxspeed 38400 txspeed 38400 flowcontrol hardware vot... rabotaet... s inout tozhe rabotaet... 1.5>Q: CHto za nomera 20xx, 40xx, 60xx portov na Cisco ? >A: (Dmitri Beloslioudtsev) A eto raznye rezhimy raboty telnet: Telnet port 20xx Telnet raw port 40xx Telnet binary port 60xx A>: (Eugene Zhilitsky) Porty 30hh, 50hh, 70hh - to zhe samoe, no dlya rotary. 1.6>Q: A ne podskazhet li vseznayushchij All, kak v kiske 2503 nastpoit' AUX popt dlya podklyucheniya k nemu modema s vydelennoj liniej. Ha mapshputepe s dpugoj stopony vydelenki ostalis' tol'ko asinhponnye popty. >A: (Dmitry Morozovsky) int a0 ip unn e0 enc ppp keep 10 asy mode dedicated asy def rou asy dyn rou li a 0 speed 38400 flow hard esc NONE stopbits 1 Plyus konfiguraciya modema (dlya reverse telnet nuzhny modem inout & tran in telnet) 1.7>Q: Kak zastavit' rabotat' NT, Win c kiskoj po nul'-modemu ? >A: (Alexander Karpoff) ppp cherez Zelaksy i s 95, i s NT rabotayut bez problem. A nado vsego-to shodit' na http://www.mindspring.com/~kewells/net/ i skachat' neobhodimye *.inf. [19.07.2000] (zaruba@artelecom.ru) predpochitayu skachivat' s ftp://ftp.zelax.ru/pub/soft/mdmzelax.inf http://www.zelax.ru/faq/faq76.html P.S. (DY) govoryat eshche chto, mozhno postavit' na NT vmesto modema - X.25 pad. P.P.S. (DY) najti mdm3640t.inf ili vzyat' tut - http://cube.sut.ru/~dyer/faq/mdm3640t.inf.txt s kur'erami - rabotaet :) >A: (DY) A vot bolee polnyj sposob (otkopan gde-to u menya na diske) ============================================================================= * Area : RU.WINDOWS.NT (RU.WINDOWS.NT) * From : Dmitry Vashkovsky, 2:5020/168.121 (Pyatnica Sentyabr' 26 1997 19:23) * Subj : NT&vydelennaya liniya ============================================================================= VB> Kak sdelat' %SUBJ%? VB> Est' NT4+SP3+RAS&Routing+Motorola Premier 33.6 Predlagayu variant resheniya kotoryj rabotaet u menya s maya i proveren moimi znakomymi, u nih tozhe rabotaet na ura :) I tak provajder predostavil vam vydelennyyu liniyu na kotoroj s vashej storony visit modem, pri vklyuchenii on srazu podklyuchaetsya k provajderu i nikakimi obychnymi sredstvami nt ego neudaetsya uvidet'. Srazu skazhu, chto v resurskite po etomu povodu napisano vsego dve strochki, chto vy dolzhny rabotat' po null modem, eto pochti pravil'no. Ha samom dele vy imitiruete x25. Pervoe chto vy dolzhny sdelat' sohranit' na vsyakij sluchaj iz direktorii ras svoj fajl pad.inf i vmesto nego polozhit' novyj ya vzyal iz nt3.51 fajl modem.inf i otredaktiroval ego (tol'ko v nem! v nt4 net podhodyashchego opisanie null modem) vybrosil iz nego opisaniya vseh modemov ostavil tol'ko nekotoruyu obshchuyu informaciyu i otredaktirovannoe pod neobhodimuyu nam situaciyu opisanie nulmodema, privozhu etu chat' polnost'yu ;---------------------------------------- [Null Modem 33600] CALLBACK_TIME=10 DEFAULTOFF= MAXCARRIERBPS=33600 MAXCONNECTBPS=33600 COMMAND= CONNECT= ;---------------------------------------- poyavivshemsya menyu vybiraem Install X25 Pad gde v predlagaemom menyu estestvenno vybiraem Null Modem, dalee podtverzhdaem vse, chto mozhno ne zabyv skazat', chto dannoe ustrojstvo rabotaet tol'ko na dial out i po prodotokolu tcp/ip :) nastraivaya dialup v chasti posvyashchennoj h25 u vas neskol'ko strok v pervoj s pomoshch'yu strelki vniz vybiraete vash nulmodem v ostal'nyh pishite lyubuyu erundu (ya nakpisal imya provajdera). Vse mozhete spokojno rabotat'. Tol'ko ne zabud'te v opisanii porta ukazat' tuzhe skorost', chto i opisanii nulmodema. Esli vam negde vzyat' modem.inf ot nt3.51 mozhete zabrat' moj uzhe otredaktirovannyj pad.inf (pravda pod 19200, nu da cifirki perebit' ne slozhno) u menya po ftp:\\www.advance.com.ru on tam lezhit pryamo v korne. Dmitry dva@skydive.ru http:\\www.advance.com.ru/skydiver ZY: posle togo kak u vas vse zarabotaet ne zabud'te ugostit' menya pivom ============================================================================= >A: (DY) Provozivshis' kakoe-to vremya s http://www.mindspring.com/~kewells/net/ poshel neskol'ko drugim putem. Pishu po pamyati, chto vspomnil. So storony kiski - modemcap entry usr_ll:FD=&f1&l1:AA=A line X modem autoconfigure type usr_ll So storony Win,WinNT Stavyatsya normal'nye drajvera ot ustanovlenogo modema. Konfigurim modem AT&F1 AT&W Variant 1. V nastrojkah modema (tam gde chto-to tipa advanced/extra settings) stavim strochku inicializacii AT&L1 Variant 2. V strochke s telefonom stavim X3T1 (v takom variante pozhaluj budet rabotat' lyuboj modem, kotoryj i ne umeet po pasportu rezhim Leased Line) I eshche o tom zhe - http://www.psc.ru/sergey/TehSerenada/CISCO/ONLINE/wint4ll.html 1.8>Q: A znaet li kto-nibud' , mozhno li peredavat' zvonyashchemu abonentu adresa DNS avtomaticheski s kisy ? YA slyshal , chto takoe byvaet. >A: (Sergiy Zhuk) async-bootp dns-server 192.168.3.100 192.168.3.110 eto DNS ^^^ async-bootp nbns-server 192.168.3.2 192.168.2.2 a eto netbios (wins) 1.9>Q: Stoit kiska 3640 u kotoroj ustanovlen modul' Mica-modem na 30 modemov i modul' E1 soedinennyj s ATS. Kogda ya delayu komandu sh use to vizhu kartinku takogo plana > 66 tty 66 pupkin ... > 55 tty 55 vasya ... Kak mne uznat' po kakomu tajmslotu v potoke E1 vyshel pol'zovatel' t.e. sushchestvuet li privyazka line k bchannel, esli net to mozhno li eto zdelat'. >A: (Andrew Lun) sh modem csm 1.10>Q: Imeetsya Cisco 1005. Posledovatel'nyj port skonfigurirovan kak sinhronnyj. Podskazhite, pls, kak ee zastavit' rabotat' s asihronnym modemom? >A: (Dmitry Morozovsky) Dlya 1005 sync-async pereklyuchaetsya softom. Hachinaya s 2520/2522 -- komandoj physical-layer async na interfejse (kstati, polezno pomnit', chto pri etom menyaetsya SNMP nomer interfejsa). 1.11>Q: Probros uucp-shnikov. >A: (DY) pro RADIUS vzyato iz inet-admins, za tochnost' ne ruchayus'. a. NAS, TACACS/RADIUS TACACS: group = uucp { default service = permit service = exec { noescape = true autocmd = "telnet aaa.bbb.ccc.ddd 540 /stream" } } Dlya RADIUS, (Dmitry Morozovsky) /var/spool/uucp/public/.rhosts: nas0 ciscoTS nas1 ciscoTS (Basil Dolmatov) - NAS prihodit so specificheskim imenem "ciscoTS"... Imenno ego i nado razreshat'... NAS: (Taras Heychenko) rlogin trusted-remoteuser-source local rlogin trusted-localuser-source local b. Clients sys ot taylor-uucp myname client system host time any call-login uuclient call-password cl.password port port1 phone XXXXXXX chat sername: \L\r assword: \P\r ogin: \L\r sword: \P\r system.pat ot UUPC/@ 200 gGt N g(%L_GWSIZE%,%L_GPSIZE%)/g(%R_GWSIZE%,%R_GPSIZE%) "" \W20\c name--name--name \p\p\L sword:-\L-sword:-\L-sword:-\L-sword: \p\P ->-> \crlogin\sUUHOST\r ogin--ogin--ogin \p\p\L sword:-\L-sword:-\L-sword: \p\P UUHOST zamenit' na svoe Dlya sluchaya s autocommand "->-> \crlogin\sUUHOST\r " mozhno vykinut' 1.12>Q: Obratnyj zvonok s Cisco v Windows >A: (Vyacheslav V. Fedorov) Ha Cisco 2511: version 11. service exec-callback ... aaa authentication login execcheck tacacs+ aaa authentication ppp ppp_list tacacs+ ... interface Async2 ip unnumbered Ethernet0 ip tcp header-compression passive encapsulation ppp async mode interactive peer default ip address x.x.x.x ppp callback initiate ppp authentication chap ppp_list .... line 2 autoselect during-login autoselect ppp script modem-off-hook offhook script callback idc login authentication execcheck modem InOut transport input all escape-character NONE callback forced-wait 30 callback nodsr-wait 10000 stopbits 1 rxspeed 57600 txspeed 57600 flowcontrol hardware ..... Ha servere gde tacacs+: V fajle tacacs.config user= mylogin { global = cleartext "xxxxxxxxxx" service=ppp protocol = lcp { callback-dialstring = 388888 } service=ppp protocol=ip { } service=exec { callback-dialstring = 388888 callback-line=2 nocallback-verify=1 } } >A: (Dmitry Valdov) Dlya togo, chtob yuzer mog vvodit' nomer, iz takaksa dolzhno prihodit' callback-dialstring = "" V obshchem: cisco: service exec-callback (eto nuzhno tol'ko v sluchae, esli predpolagaetsya ispol'zovat' callback so skriptami.) .... chat-script dial ABORT ERROR TIMEOUT 50 "" "AT" "OK" "ATD\T" "CONNECT" .... interface group-async 1 ppp authentication pap ppp callback accept ... line 1 60 script callback micadial rotary 1 callback forced-wait 10 autoselect during-login autoselect ppp ..... V takakse: group = callback { ..... service ppp protocol = lcp { callback-dialstring = "" callback-rotary = 1 nocallback-verify = 1 } } user ..... { member = callback service = exec { ..... callback-dialstring = "" nocallback-verify = 1 callback-rotary = 1 } } Mastdajka sama VSEGDA zaprashivaet callback po cbcp pri lyubom zvonke s nee. Esli ej ne otkazyvayut, to ono zaprashivaet nomer telefona. Dlya HT nado eto vse ukazat' v yavnom vide. >A: (Andy Igoshin) ftp://ftp.vsu.ru/pub/hardware/cisco/callback 1.13>Q: Kak svyazat' dve Kiski po E1? >A: (Gosha Zafievsky), prislal (Oleh Hrynchuk) Konfig ppimepno sleduyushchij (odinakovyj v sluchae 5300 & 3600): controller E1 ZZZ linecode hdb3 | framing CRC4 | |ti dva papametpa zavisyat ot kanaloobp. obopudovaniya clock source line primary | Ha 3600 est' tol'ko v 12.0 channel-group 1 timeslots 1-31 interface serialZZZ:1 encapsulation hdlc ip address a.b.c.d x.y.z.t ip route 0.0.0.0 0.0.0.0 serialZZZ:1 CHto podstavlyaetsya vmesto ZZZ zavisit ot konkpetnoj zhelezki... 1.14>Q: Mozhno li opganizovat' IP kanal chepez AUX popt s ppyamym podklyucheniem k SOM'u na HT (dumayu chepez nul'-modem), ili ya mnogo hochu? >A: (??), prislal (Oleh Hrynchuk) Net problem. Nedavno samomu ponadobilos' - u cisco3640 ne bylo Ethernet. Nemnogo prishlos' povozit'sya s kabelem, raspajka takaya RJ-45 - DB-25 1-5 2-6,8 3-3 4-7 5-7 6-2 7-20 8-4 Vse ostal'noe kak obychno na asin. portu. [13.06.2000] 1.14>Q: Kak luchshe nastroit' modem na async portu ? >A: (Mathey M. Teplov) YA, naprimer, da i mnogie voobshche sovetuyut sdelat' tak: 1) ubivaesh' modem autoconfigure putem propisyvaniya no modem autoconfigure 2) inicializiruesh' liniyu, kak 115200 8,n,1 ! chat-script RESET_SCRIPT ABORT BUSY ABORT ERROR ABORT "NO CARRIER" ABORT "NO ANSWER" AT&F1 OK ! line x speed 115200 databits 8 flowcontrol hardware stopbits 1 parity none no modem autoconfigure script reset RESET_SCRIPT ! i posle etogo zhestko propisyvaesh' v F1 profil' v Courier sleduyushchee: &A3&B1&C1&D2&G2&H1&I0&K1&L0&M4&N0&P1&R2&S0&T5&X0&Y0%N6 i vystavlyaesh' na nem dzhampera daby on gruzilsya iz F1. Provereno na gor'kom opyte. [05.09.2000] 1.15>Q: Callback na linuh >A: (Eugene Crosser) http://www.tartu.customs.ee/linux/callback.shtml YA sam ne proveryal. Ha moj vkus skript krivoj, no ideya yasna. ===========================================================

2. FR

=========================================================== 2.1>Q: Frame Relay & Unnumbered interface Kto-to nekotopoe vpemya nazad tut pisal, chto IP unnumbered na FrameRelay subinterfaces ne byvaet. A u menya poluchilos'. >A: (Alex Tutubalin) Ppimepno tak: Interface Serial 0 no ip address frame-relay lmi-type ansi Interface Serial 0.1 point-to-point frame-relay interface-dlci 16 ietf ip unnumbered ethernet 0 ip route 192.168.111.48 255.255.255.240 Serial 0.1 C dpugoj stopony stoit FreeBSD + Cronyx Sigma-22. Tam vse sdelano ppimepno tak: cxconfig cx0 hdlc fr +extclock ifconfig cx0 192.128.111.49 195.54.222.201 route add default 192.168.111.201 .49 - Ethernet na etoj zhe mashine .201 - Ethernet na Cisco >A: (Alex Zinin) V sluchae s unnumbered inkapsulyaciya igraet tol'ko kosvennuyu rol'. A sabinterfejsy -- lish' chastnyj sluchaj. Obshchee pravilo takoe -- ip unnumbered mozhno stavit' tol'ko na interfejsah, kotorye Cisco rassmatrivaet kak p-t-p. Dlya WAN interfejsov tip opredelyaetsya inkapsulyaciej. T.e. hdlc - ptp, ppp-ptp, slip-ptp, fr-ptm, x25-ptm, smds-ptm Otdel'nyj sluchaj -- dialer. On ne menyaet tipa interfejsa i rabotaet isklyuchitel'no samostoyatel'no poverh data-link urovnya. V sluchae zhe s sabinterfejsami, vy mozhete razbit' odin fizicheskij p-t-m na neskol'ko p-t-p i p-t-m interfejsov. Sootvetstvenno na p-t-p mozhno ispol'zovat' unnumbered. ===========================================================

3. X25

=========================================================== Avtor otvetov - Eugene Zhilitsky, esli ne ukazano inoe. 3.1>Q: [DOS-COM1]--a1[Cisco2509]--[Cisco2522]-- -[?]--[UNIX-APP] Ha Cisco2522 vypolnyaetsya translyaciya TCP v X.25, a 2509 prosto delaet telnet na transliruemyj adres. HO, zabrat' s UHIHmashiny mozhno, a polozhit' net. Proboval translyacii i binary i stream, i telnet /stream i s inymi parametrami i to i drugoe. I profajl yuzal tipa x29 profile aaaa 2:0 3:0 4:100 7:21 11:14, v plane eksperimenta. >A: (Eugene Zhilitsky) 4:100 - eto ochen' ploho, nepolnye pakety budut uhodit' tol'ko cherez 100*0.05=5 sekund! 1. translyaciya i telnet dolzhny byt' stream. 2. x29 profile aaa 1:0 2:0 3:2 4:5 5:0 8:0 9:0 10:0 12:0 15:0 22:0 3:2 - eto dlya "profilaktiki", chtoby po ^M pakety uhodili srazu zhe, inogda eto meshaet (v ochen' redkih special'nyh prilozheniyah). Mozhno stavit' 3:0. 3. na asinhronnom portu (a1[Cisco2509]), k kotoromu podklyuchena dosovaya tachka: escape-character NONE telnet transparent 4. Dlya yuzera, kotorym dosovaya tachka zahodit na pervuyu cisku - noesc. 5. Ha vseh vty, kotorye mogut ispol'zovat'sya dlya translyacii nado takzhe: escape-character NONE telnet transparent 6. Vezde vmesto etih dvuh strok mozhno ispol'zovat' odnu: terminal-type download |tot sposob podskazali guru iz RU.CISCO (kto konkretno ne pomnyu :-(. Hu vrode by bol'she nichego ne zabyl :-))))) Dolzhno rabotat'. 3.2>Q: Kak nastraivat' h25? >A: Est' prostoe empiricheskoe pravilo: vse parametry labp (hdlc) i h25 dolzhny byt' odinakovymi na oboih koncah linka, krome logicheskogo DTE/DCE - on dolzhen byt' _raznym_. Krome togo, ne nado zabyvat', chto razmer paketa na vtorom urovne (lapb) na Ciske ukazyvaetsya v _bitah_, a u bol'shinstva drugih proizvoditelej - v _bajtah_. 3.3>Q: Horosho, no na moem h25-box'e est' parametr "Gruppa logicheskih kanalov", a v Ciske ya takogo ne nashel. CHto delat'? >A: Kazhdaya edinica v etom parametre dobavlyaet 256 k nomeru logicheskogo kanala. Haprimer, na h25-box'e takie parametry: Gruppa logicheskih kanalov - 4 Homer pervogo Two-way VC - 1 Kolichestvo Two-way VC - 16 Togda na Ciske nado vystavit': x25 ltc 1025 x25 htc 1040 3.4>Q: YA propisal translyaciyu h25-TSR, no ona ne rabotaet, Ciska vmesto nee vydaet Username: (zapuskaetsya exec). CHto delat'? >A: U vas dlya translyacii ispol'zuetsya takoj zhe h25 adres kak i v x25 address na Serial. Ispol'zovanie Call User Data (cud) v translyacii ne spasaet. Adresa dolzhny byt' raznymi, naprimer, rasshir'te h25 adres v translyacii s pomoshch'yu podadresov. 3.5>Q: Iz-za mestnyh uslovij ispol'zovat' podadresa ya ne mogu. >A: Togda prosto udalite x25 address iz konfiguracii Serial. |tot parametr ispol'zuetsya v ishodyashchih paketah vyzova kak adres istochnika. Esli ego udalit', to pakety vyzova budut uhodit' s pustym adresom istochnika. Prakticheski vse h25 seti trebuyut, chtoby adres istochnika byl ukazan pravil'no, libo byl pustym, tak chto vse dolzhno rabotat' i bez nego. 3.6>Q: Ura! Translyaciya zarabotala. Ho zadacha pomenyalas', nado chtoby na vyzov s Call User Data (cud) zapuskalas' translyaciya, a na vyzov po tomu zhe adresu bez cud zapuskalsya exec. >A: Propishite etot adres cherez x25 routing x25 route alias Serial 3.7>Q: Hi y kogo net nastpoek Cisco <--> Eicon po X.25. Hotya by s stopony Cisco. PPP i Frame Relay polychilos', a vot X.25 nikak. A nado. >A: (john gladkih) direct connection? interface Serial1 description x.25 4 m$ eXchange bandwidth 5 no ip address no ip directed-broadcast encapsulation x25 dce ietf no ip mroute-cache x25 address ADDRESS x25 htc 32 x25 win 7 x25 wout 7 x25 accept-reverse x25 nonzero-dte-cause clockrate 4800 lapb T1 500 lapb N2 9 [13.06.2000] 3.8>Q: Podskazhite pozhalujsta kak detal'no otrabatyvaet takoj "kusochek" translate translate x25 03 cud 4411 profile NUL ppp ............ >A: (Vasily Ivanov) Ubogo on otpabatyvaet, t.k. dlya nastpoek so stopony kiski hvataet dannye s pepvogo popavshegosya intepfejsa. Ostavlen dlya sovmestimosti so stapymi IOSami. Gopazdo luchshe ispol'zovat' translate x25 12345 virtual-template 1. A detal'no s kaptinkami smotpi na http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/12cgcr/dial_c/dcpt.htm [05.09.2000] 3.9>Q: ya tut vspomnil kak s polgoda nazad obsuzhdali problemu pad dostupa cherez xot i kogda x.25 set' ne hotela prinimat' vyzovy s facilities kotorye pri xot neizbezhny. eshche aktual'no? mogu dat' recept. no on trebuet 12.1 ;) (kak ya pomnyu v diskussii byl eshche i annex-g? togda 12.1 byt' dolzhen) >A: (john gladkih) ok. ruter s annex-g, on zhe lokal'nyj x25 switch: service pad to-xot service pad from-xot service tcp-keepalives-in service tcp-keepalives-out ! frame-relay switching ! x25 profile test dte x25 address 61273 x25 htc 32 x25 win 7 x25 wout 7 x25 ips 1024 x25 ops 1024 x25 nonzero-dte-cause 1> x25 subscribe flow-control never lapb modulo 128 2> x25 routing acknowledge local ! interface Serial0 bandwidth 64 no ip address encapsulation frame-relay IETF frame-relay interface-dlci 25 x25-profile test frame-relay lmi-type ansi ! x25 route ^6127305 xot 10.10.0.21 xot-keepalive-period 10 3> x25 route .* source ^$ substitute-source 6127305999 interface Serial0 dlci 3> 25 x25 route .* interface Serial0 dlci 25 1> otklyuchenie soglasovaniya flow-control na interfejse dlya vyzovov. 2> razreshit' lokal'nuyu peresborku paketov. 3> pad call cherez xot prihodit c pustym src address i my src tut podmenyaem na 6127305999 s drugoj storony xot nichego osobennogo: x25 route ^612.* xot 10.10.0.118 xot-keepalive-period 10 xot-keepalive-period tut chisto dlya proformy. ===========================================================

4. ACL

=========================================================== 4.1>Q: Rekomendacii po access-lists dlya zashchity ot atak iz interneta. Nekotorye rekomendacii i soobrazheniya. aaa.bbb.ccc.ddd, naa.nbb.ncc.ndd - sootvetstvenno svoi set' i maska. wba.wbb.wbc.wbd - wildcard bits Vnimanie !!! v access-list ispol'zuetsya ne netmask, a wildcard bits. Est' zhutkaya formula, no ya predpochitayu pol'zovatsya takoj - WB=255-NM takim obrazom, esli netmask 255.255.255.0 v access-list pishetsya 0.0.0.255 ! deny all RFC1597 & default no access-list 101 access-list 101 deny ip host 0.0.0.0 any access-list 101 deny ip 10.0.0.0 0.255.255.255 any access-list 101 deny ip 127.0.0.0 0.255.255.255 any access-list 101 deny ip 172.16.0.0 0.15.255.255 any access-list 101 deny ip 192.168.0.0 0.0.255.255 any ! deny ip spoofing access-list 101 deny ip aaa.bbb.ccc.ddd wba.wbb.wbc.wbd any ! deny netbios access-list 101 deny udp any any range 137 139 log access-list 101 deny tcp any any range 137 139 log ! deny Back-Orifice access-list 101 deny udp any any eq 31337 log ! deny telnet access-list 101 deny tcp any any eq telnet log ! deny unix r-commands and printer, NFS, X11, syslog. tftp access-list 101 deny tcp any any range exec lpd log access-list 101 deny udp any any eq sunrpc log access-list 101 deny tcp any any eq sunrpc log access-list 101 deny udp any any eq xdmcp log access-list 101 deny tcp any any eq 177 log access-list 101 deny tcp any any range 6000 6063 log access-list 101 deny udp any any range 6000 6063 log access-list 101 deny udp any any range biff syslog log access-list 101 deny tcp any any eq 11 log access-list 101 deny udp any any eq tftp log ! permit all access-list 101 permit ip any any no access-list 102 access-list 102 permit ip aaa.bbb.ccc.ddd wba.wbb.wbc.wbd any access-list 102 deny ip any any int XXX ip access-group 101 in ip access-group 102 out 4.2>Q: Kin'te, pozhalujsta, primer access-list'a ( nado zakryt' dlya dostupa izvne vo vnutrennyuyu set' vse porty - ostavit' tol'ko vozmozhnost' raboty po http i e-mail) Cisco - 1601 Zaranee blagodaren. >A: (Alex Bakhtin) Itak. Est' dve strategii po ustanovke aksess-listov: 1. Zakryt' vse opasnoe, otkryt' vse ostal'noe. 2. Otkryt' vse nuzhnoe, zakryt' vse ostal'noe. V zdeshnem FAQe, kotoryj byl porekomendovan, imeetsya primer, napisanyj imenno po pervomu principu. He budem obsuzhdat' preimushchestva i nedostatki dannogo podhoda, naskol'ko ya ponimayu, u vas est' zhelanie ispol'zovat' vtoroj. YA popytayus' opisat' dostatochno universal'nuyu metodiku, kotoraya mozhet byt' ispol'zovana pri postroenii zashchity vtorogo tipa, a zatem privesti primer real'no rabotayushchej konfiguracii. Srazu hochu skazat', chto vse nizhenapisanoe - eto chisto moe IMHO. Predpolagaetsya razrabotka access-lista, ogranichivayushchego vozmozhnosti dostupa _izvne_ v lokal'nuyu set', a ne ogranicheniya vozmozhnostej po vyhodu naruzhu iz lokal'noj seti. Itak. Hachat' imeet smysl s sistematizacii togo, chto my, sobstvenno hotim poluchit'. Dlya etogo predlagayu vystroit' sleduyushchuyu tablicu: ! ! ! ! ! !www !mail!ftp!binkd!i tak dalee - zdes' perechilyaem servisy ! ! ! ! !dostup k kotorym my hotim predostavit' ! ! ! ! !pol'zovatelyam "izvne" ------------!----!----!---!-----!---------------------------------------- www.qq.ru ! X ! ! ! ! relay.qq.ru ! ! X ! ! ! ftp.qq.ru ! ! ! X ! ! any ! ! ! ! X ! zdes' hosty/ gruppy hostov, kotorye predostavlyayut sootvetstvuyushchie servisy. Poryadok raspolozheniya hostov v tablice vazhen. Est' dva pravila: a. Obshchie opredeleniya neobhodimo raspolagat' kak mozhno nizhe. To est' host 10.0.1.1/32 dolzhen byt' raspolozhen _vyshe_ chem subnet 10.0.1.0/24. Sootvetstvenno v samuyu poslednyuyu strochku pishetsya chto-to tipa any. b. V sluchae, esli po pravilu a. okazyvaetsya, chto poryadok kakih-to konkretnyh strok mozhet byt' lyubym (kak v nashem primere www, relay i ftp mogut byt' perechisleny v lyubom poryadke, no obyazatel'no vyshe chem any), to na bolee vysokie pozicii nado stavit' hosty, kolichestvo obrashchenij k kotorym po otmechennym servisam predpolagaetsya bol'shim. V nashem sluchae my predpolagaem, chto osnovnye zaprosy budut postupat' na www server, zatem budet peredavat'sya kakoe-to kolichestvo pochty i uzh sovsem malo budet zaprosov na ftp. Posle sostavleniya, proverki i, po vozmozhnosti, optimizacii takoj tablicy (voobshche eto process dostatochno tvorcheskij i netrivial'nyj;-)) mozhno perehodit' sobstvenno k napisaniyu pervoj versii access-lista. Pervaya versiya budet prakticheski kal'koj nashej tablicy. ip access-list extended Firewall permit tcp any host www.qq.ru eq www permit tcp any host relay.qq.ru eq smtp permit tcp any host ftp.qq.ru eq ftp permit tcp any any eq 24554 Poslednyaya stroka po umolchaniyu prinimaetsya za deny ip any any. Fakticheski, postroenie pervoj versii access-lista zakoncheno. CHto my delaem, chtoby prodolzhat' razvivat' etot access-list? V konec lista my dobavlyaem odnu strochku deny ip any any log kotoraya ne tol'ko zapretit ves' ostal'noj trafik, chto bylo sdelano po-umolchaniyu, no i zastavit' vydavat' na konsol'/monitor/syslog soobshcheniya o paketah, popadayushchih pod eto pravilo. I dalee, v zavisimosti ot togo, kakie servisy ne byli uchteny v nashem liste(soobshcheniya ob otbroshenyh paketah budut sypat'sya na konsol'), mozhno budet dorabatyvat' nash access-list. Vot primery soobshchenij: %SEC-6-IPACCESSLOGP: list firewall denied tcp xxx.xxx.xx.xx(1418) -> %xxx.xxx.xxx.xx(23), 1 packet %SEC-6-IPACCESSLOGP: list firewall denied udp xxx.xxx.xxx.xxx(4000) -> %xxx.xxx.xxx.xx(1038), 1 packet %SEC-6-IPACCESSLOGP: list firewall denied udp xxx.xxx.xxx.xxx(53) -> %xxx.xxx.xxx.xx(1041), 1 packet %SEC-6-IPACCESSLOGP: list firewall denied udp xxx.xxx.xxx.xxx(53) -> %xxx.xxx.xxx.xx(1044), 1 packet %SEC-6-IPACCESSLOGP: list firewall denied udp xxx.xxx.xxx.xxx(53) -> %xxx.xxx.xxx.xx(1047), 1 packet %SEC-6-IPACCESSLOGP: list firewall denied udp xxx.xxx.xx.xx(49869) -> %xxx.xxx.xxx.xx(33456), 1 packet %SEC-6-IPACCESSLOGP: list firewall denied udp xxx.xxx.xx.xx(49869) -> %xxx.xxx.xxx.xx(33458), 1 packet Vot sobstvenno i vse;) Hado ne zabyvat' otkryvat' _na_vhod_ port domain - chtoby k nam prihodili otvety na nashi dns zaprosy. active ftp - eto voobshche otdel'naya pesnya. Vot primer real'no rabotayushchego access-lista, on, razumeetsya, ne idealen, no rabotaet;) Da, nado ne zabyvat' otkryvat' established. Posle znaka ; - moj kommentarii. =================== ip access-list extended firewall permit tcp any any eq smtp ; vse hosty prinimayut pochtu po smtp permit tcp any any eq domain ; dve strochki na dns permit udp any any eq domain ; permit tcp any any eq 22 ; ssh permit tcp any host fido.qq.ru eq 24554 ; binkd permit tcp any any established ; vot ono samoe permit tcp any host www.qq.ru eq www ; www-servera permit tcp any host images.qq.ru eq www permit tcp any host www.qq.ru range 8100 8104 ; dlya ruskoj kodirovki permit tcp any host images.qq.ru range 8100 8104 permit udp any any eq ntp ; vse mashiny mogut poluchat' vremya s vneshnih ntp permit tcp any any range 40000 44999 ; uzhe ne pomnyu dlya chego:-(( permit tcp any any eq ident permit icmp any any permit tcp any eq ftp-data any gt 1024; dlya active-ftp deny ip any any log =================== 4.3>Q: Kak sdelat' transparent-proxy ? >A: (DY) Vse opisano na http://squid.nlanr.net/Squid/FAQ/FAQ-17.html 4.4>Q: Dynamic ACL. >A: Prislal (Oleh Hrynchuk) You can use timed access-lists in IOS 12.x You will need the router to synch to a clock source for accuracy though.. for example: int ser0/0 ip access-group 101 in ! access-list 101 remark --FOR THE QUAKE 3 PLAYERS AT THE OFFICE-- access-list 101 permit udp any any range 27850 27999 time-range lunchtime access-list 101 deny any any ! time-range lunchtime periodic weekdays 12:00 to 14:00 periodic weekend 00:00 to 23:59 ! ntp source loopback0 ntp server ! [13.06.2000] 4.5>Q: Kak razreshit' zahodit' na kisku telnetom tol'ko s opredelennyh hostov ? >A: (Gosha Zafievsky) access-list 11 permit host 192.168.1.1 line vty 0 4 access-class 11 in ===========================================================

5. Traffic-shape

=========================================================== 5.1>Q: Kak zazhat' ishodyashchij ftp-trafik ? >A: (Vasily Ivanov) Dlya Active-FTP access-list 115 permit tcp host 123.123.123.123 eq ftp-data any gt 1023 Dlya Passive-FTP access-list 115 permit tcp host 123.123.123.123 any eq ftp 5.2>Q: Kak sdelat' traffic-shape na tun ? >A: (DY) Vot zavalyalsya kusok rabochego konfiga ot 4000. interface Tunnel1 ip address xxx.xxx.xxx.xxx 255.255.255.252 tunnel source aaa.aaa.aaa.aaa tunnel destination bbb.bbb.bbb.bbb ! interface Ethernet0 ip address aaa.aaa.aaa.aaa 255.255.255.224 secondary traffic-shape group 122 32000 8000 8000 1000 ! no access-list 122 access-list 122 permit ip host aaa.aaa.aaa.aaa host bbb.bbb.bbb.bbb access-list 122 deny ip any any P.S. Vyacheslav Furist Pomoemu luchshe bylo by access-list 122 permit gre host aaa.aaa.aaa.aaa host bbb.bbb.bbb.bbb 5.3>Q: Kak zazhat' vhodyashchij trafik? >A: "Boris Mikhailov" Pri vhode pomozhet policyroute, esli mochi processora hvatit. Eshche dobavlyu chto do 11.2(gde-to 12~13) traffic-shap krivo zatykaetsya i ne shejpit (ochen' chastyj vopros byl ran'she). access-list 180 opisyvaet tpaffik, kotopyj nado shejpit' interface Loopback1 ip address 192.168.11.1 255.255.255.255 traffic-shape rate 64000 ! interface Serial0 ip policy route-map incoming-packets ! access-list 180 permit ip any 192.168.1.0 0.0.0.255 ! route-map incoming-packets permit 10 match ip address 180 set interface Loopback1 5.4>Q: Bandwith, queue >A: (Alex Bakhtin) Osnovnym parametrom, kotoryj vliyaet na raspredelenie polosy propuskaniya pri custom queuing, yavlyaetsya byte-count. queue length na eto delo vliyaet malo. Itak. Dopustim, u nas est' takoj vot queue-list: c4000-m#sh queueing custom Current custom queue configuration: List Queue Args 1 1 byte-count 6000 1 2 byte-count 3000 1 3 byte-count 4500 Ostal'nye ocheredi po 1500. Ponyatno, chto napryamuyu bandwith dlya kazhdoj iz ocheredej ne zadaetsya. Zapolnenie ocheredej, ponyatno, proishodit na osnovanii kakih-to kriteriev, kotorye ya v dannom sluchae ne uchityvayu. Dal'she, my nachinaem obhodit' vse 17 ocheredej nachinaya s nulevoj - 1. Peredaem 1500 bajt iz ocheredi 0 (esli tam est' pakety) 2. Peredaem 6000 bajt iz ocheredi 1 3. Peredaem 3000 bajt iz ocheredi 2 4. Peredaem 4500 bajt iz ocheredi 3 5. Peredaem 1500 bajt iz ocheredi 4 ..... 17. Peredaem 1500 bajt iz ocheredi 16 Dopustim, chto my ispol'zuem dlya nashego trafika tol'ko pervye 4 ocheredi - v ostal'nye ocheredi trafik nikogda ne popadaet. Sootvetvtsenno, v srednem za odin cikl budet peredano S=1500(q0)+6000(q1)+3000(q2)+4500(q3)+1500(q4)=16500 bajt Sootvetstvenno, pod Q0 budet vydeleno B0=1500/16500~=9% BW B1~=36% BW B2~=18% BW B3~=28% BW B4~=9% BW To est' real'nuyu polosu propuskaniya podzhelyat proporcional'no ispol'zuemye ocheredi. Sootvetstvenno, real'nyj bandwith po kazhdoj ocheredi zadaetsya s pomoshch'yu parametra byte-count, no indirectly, tak kak on zavisit ot chisla ispol'zuemyh real'no ocheredej i ot propusknoj sposobnosti interfejsa. Dannye znacheniya, razumeetsya, budut verny tol'ko pri dostatochno ser'eznom usrednenii. Svyazano eto s tem, chto esli byte-count ischerpyvaetsya v processe peredachi paketa, paket vse ravno peredaetsya do konca - to est' real'naya zanimaemaya polosa budet bol'she. Vse, chto napisano vyshe - ne bolee chem nekie teoreticheskie vykladki pri rabote v ideal'nyh usloviyah. Real'no vse eti znacheniya nado podbirat', analiziruya srednij razmer paketa i ne tol'ko;) 5.5>Q: Traffic-shape na Loopback'e, Tunnel'e est' ili net ? >A: (Alex Bakhtin) Hekotoroe vremya nazad mne ponadobilsya shejper na BVI interfejse v svyazi s chem ya dostatochno ser'ezno zanimalsya etoj problemoj. Itak. 1. SHejper rabotaet. V 12.x - <=12.0(2a), v 11.3 tozhe do kakoj-to versii. 2. SHejper rabotaet krivo - shejpit tol'ko process-switched pakety. (btw, eto kak raz prichina togo, chto shejper na gruppu asinkov cherez policy-route rabotaet) 3. SHejper na virtual'nyh interfejsah (kotorymi yavlyayutsya BVI, loopback i Tunnel) unsupported by Cisco. To est' oficial'no ego net. To, chto on ran'she byl - eto bag takoj v parsere konfigov/komandnoj stroki, kotoryj pozvolyal ego vklyuchat'. YA otkryval po etomu povodu kejs v ciske - mne predlozhili poslat' rekvest na fichu. Tak chto, boyus', pro zamechatel'nyj sposob shejpit' na lupbake pridetsya zabyt' esli ispol'zuetsya 11.3 ili 12.x:-(( 5.6>Q: Kak zazhat' ftp ? >A: (Alexander Kazakov) V obshchem ya otdal postoyannye 32k dlya ftp. Vse pabotaet i vpolne menya ustpaivaet. fpejm-pelej delat' poka ne stal, budu snachala ppobovat' na stendovoj koshke. kak obeshchal - pabochij konfig: === Cut === interface Serial2/0 description xxx XXX ip address aaa.bbb.ccc.ddd 255.255.255.0 no ip route-cache no ip mroute-cache bandwidth 128 ipx network B021 ipx accounting priority-group 2 traffic-shape group 191 32000 8000 8000 1000 ! access-list 191 permit tcp any any eq ftp access-list 191 permit tcp any any eq ftp-data priority-list 2 protocol ip medium list 101 priority-list 2 protocol ipx low priority-list 2 protocol ip high tcp telnet priority-list 2 protocol ip high udp snmp priority-list 2 protocol ip high tcp echo priority-list 2 protocol ip high udp echo ===========================================================

6. Routing

=========================================================== 6.1>Q: Est' dve Cisco2511, kotorye dolzhny soedinyatsya dvumya linkami, odin cherez serial, vtoroj cherez async, oba linka po vydelenkah. V etom problem net, no hochetsya imet' ODIH bekap cherez kommutirumuyu liniyu. To est' nado, chto by bakap podnimalsya tol'ko togda kogda OBA linka propadut. >A: (Vasily Ivanov) ip route 216 Vse ppotokoly putinga imeyut metpiku <= 200, poetomu dannaya stpochka poyavitsya v lokal'noj tablice putinga tol'ko kogda upadut oba tvoih intepfejsa. Kogda main-link vosstanovitsya, ona opyat' budet vytepta ppotokolami putinga iz tablicy, i ciska nachnet otschityvat' dialer idle-timeout do bposaniya tpuby. 6.2>Q: Podskazhite chto nado shepnut' kiske, chtoby ona annonsila ripom na Ethernet ppp-linki s maskoj /32, a ne aggregatirovala ih v podset'. >A: Dmitry Morozovsky, Mike Shoyher, Gosha Zafievsky router rip version 2 ! prosto polezno redistribute static subnets no auto-summary ! Tozhe ne pomeshaet redistribute connected subnets 6.3>Q: OSPF, RIP >A: (Alex Bakhtin) router ospf 10 redistribute connected metric 1 subnets route-map only_public_net redistribute static metric 1 subnets route-map only_public_net redistribute rip network 194.186.108.0 0.0.0.63 area 0 ! router rip version 2 redistribute connected route-map only_public_net redistribute static route-map ony_public_net redistribute ospf 10 metric 4 redistribute ospf 200 metric 4 network 194.186.108.0 neighbor 194.186.108.10 neighbor 194.186.108.138 ! Razumeetsya, stoit ip classless i ip subnet-zero. 6.4>Q: U menya set' klassa C, v kotoroj zanyaty ne vse adresa. Esli ot provajdera prihodit paket na otsutstvuyushchij adres (ili otvalivshegosya dialup-yuzera) to moya Cisco i Cisco etogo provajdera nachinayut etim paketom perebrasyvat'sya. Pochemu eto i kak ot etogo izbavit'sya. >A: (Basil (Vasily) Dolmatov) U provajdera stoit route na ves' vash klass C. V sleduyushchej (vashej) Cisco propisany tol'ko routes, kotorye ona vyyasnila iz adresov aktivnyh interfejsov i kakih- libo routing-protokolov. Ostal'noe routitsya po default route, to est' na provajdera. Kak etogo izbezhat'? V Cisco est' zamechatel'nyj interfejs Null0. Konfiguriruetsya on vsego odnoj komandoj: int Null0 ip unreachables Teper' dostatochno dobavit' eshche odin route v konfiguraciyu Cisco (predpolozhim, chto set' klassa C - 193.193.193.0/24) ip route 193.193.193.0 255.255.255.0 Null 0 100 V etom sluchae, esli adres ispol'zuetsya, i route na nego izvesten Cisco, to imenno etot route i budet aktiven (poskol'ku ego metrika men'she), esli zhe adres neizvesten, to aktivnym stanet route na Null0 i Null0 otvetit na prishedshij paket icmp !H. To est', nikakogo ping-ponga na kanale uzhe ne budet. Kstati, rekomenduetsya eshche propisat' takie zhe routes dlya private-networks, eto predotvratit ih sluchajnoe vybrasyvanie v storonu provajdera. ip route 10.0.0.0 255.0.0.0 Null0 100 ip route 172.16.0.0 255.240.0.0 Null0 100 ip route 192.168.0.0 255.255.0.0 Null0 100 6.5>Q: Est' dva kanala k provajderam, est' dve setki, kak sdelat', chtoby kazhdaya set' hodila po svoemu kanalu ? >A: (Dmitriy Yermakov) policy-routing, primer est' na CD. Dlya primera ( v ochen' prostom sluchae ) access-list 110 permit ip aaa.aaa.aaa.0 0.0.0.255 any access-list 111 permit ip bbb.bbb.bbb.0 0.0.0.255 any route-map XXXX permit 10 match ip address 110 set default interface Serial 0 route-map XXXX permit 20 match ip address 111 set default interface Serial 1 int eth 0 ip policy route-map XXXX 6.6>Q: Ne podelitsya li kto-nibud' URL ili prosto sekretom zapuska OSPF mezhdu Gated i Cisco ? >A: (Alex Bakhtin) V gated i v Cisco po umolchaniyu vystavleny raznye hello/dead intervaly. Lechitsya vystavleniem sootvetstvuyushchih intervalov v gated. P.S. (DY) v poslednih GateD mozhet i popravili, deb ip ospf pomozhet vyyasnit'. >A: (Basil (Vasily) Dolmatov) Ospf yes { backbone { authtype none; interface aaa.bbb.ccc.ddd cost 1 { retransmitinterval 5; transitdelay 1; priority 0; hellointerval 10; routerdeadinterval 40; }; }; }; import proto ospfase { ALL ; }; export proto ospfase type 1 { proto ospfase { ALL metric 1; }; proto static { All metric 1; }; proto direct { ALL metric 1; }; }; 6.7>Q: Est' staticheskij marshryt: ip route 0.0.0.0 0.0.0.0 Serial 0/0 Kak mne isklyuchit' ego iz ospf'nyh anonsov? Ubrat' redistribute static - ne predlagat' ;) >A: (Dmitry Morozovsky) 1. Ubrat' default-information originate always, ili zamenit' ego na default-information originate , esli taki nuzhno ego kuda-to anonsit' 2. Otfil'trovat' ;) distribute-list out [interface name] access-list permit 0.0.0.0 0.0.0.0 6.8>Q: Ne mog li by kto-nibud' iz uvazhaemyh guru tolkovo ob座asnit' s tochki zreniya praktiki (s nebol'shim primerchikom), chto takoe stubby areas i v kakih sluchayah ih vvedenie opravdano? Pravil'no li ya ponimayu, chto oni v obshchem-to nuzhny dlya ekonomii resursov routera? >A: (Alex Mikoutsky), prislal (Oleh Hrynchuk) V ciskah est' tri tipa tupikovyh arij - stub, totally stub, Not-so-stubby. Pro poslednie dve Hallabi mog i ne napisat'. Stub - eto takaya ariya, routeram v kotoroj ne nuzhno znat', kuda kidat' pakety, prednaznachennye external adresam. Zamet' - tol'ko external, t.e. tem, kotorye sami redistrib'yutyatsya v domen ospf. Vmesto etih anonsov ASBR budet vykidyvat' defolt marshrut dlya posylki na nego sootvetstvuyushchih paketov. Esli takaya ariya imeet neskol'ko vyhodov v bekbon, to kazhdyj ASBR buzhet slat' svoj defolt. Ot tebya zavisit, kakoj iz nih rassmatrivat' pervym, a kakoj - vtorym. |to delaetsya, yasnoe delo, metrikoj po komande na ASBR: area 1 default-cost gde ariya 1 - tipa stub. Vse ostal'nye marshruty, prihodyashchie iz drugih arij, krome external budut anonsirovat'sya. Totally stub i Not-so-stubby - eto specificheskie cisochnye prilady, pomogayushchie fil'trovat' takzhe anonsy marshrutov iz drugih arij tipa interdoman (totally stub), odnako, tol'ko v tom sluchae, esli v etoj total'no tupikovoj arii net ni odnogo external marshruta. CHtoby preodolet' poslednee ogranichenie, ariyu mozhno sdelat' tipa NSSA (nachinaya s versii 11.3). V poslednih sluchayah v ariyu voobshche budet anonsirovat'sya tol'ko defolt po komande default-information originate. Tak zhe, kak i v predydushchem sluchae, ASBRov mozhet byt' neskol'ko. YA ponyatno napisal? [03.08.2000] 6.9>Q: Hado podruzhit' na sinhronnom linke routery Nortel ARN i CISCO-3640. Sejchas oni druzhat po ppp i rip. Hochetsya, chtoby druzhili po frame-relay i ospf. >A: (Sergey Y. Afonin) Sdelano na ARN s BayRS 13.20 i CISCO 3640 IOS version 12.0 Fragment konfiga ARN (as-boundary-router true k delu ne otnositsya, on govorit to tom, chto router mozhet redistributit' vse, chto est' i ne zafil'trovano special'no; esli false - to redistributitsya tol'ko tol'ko ospf): ospf router-id xxx.xxx.xxx.234 as-boundary-router true area area-id 0.0.0.0 back back serial slot 1 connector 1 cable-type v35 bofl disabled promiscuous enabled service transparent circuit-name S11 frame-relay dlcmi management-type none back default-service pvc dlci 16 vc-state active back ip address xxx.xxx.xxx.218 mask 255.255.255.252 address-resolution arp-in-arp ospf area 0.0.0.0 mtu 1480 back arp back back back back Fragment konfika 3640 (tut tozhe lishnee est', pravda): ! interface Serial2/0 ip address xxx.xxx.xxx.217 255.255.255.252 ip access-group nasprotect out ip directed-broadcast encapsulation frame-relay ip ospf network broadcast no ip mroute-cache no keepalive no fair-queue frame-relay map ip xxx.xxx.xxx.218 16 broadcast IETF ! router ospf 13227 router-id aaa.aaa.aaa.234 redistribute connected subnets redistribute static subnets network xxx.xxx.xxx.216 0.0.0.3 area 0.0.0.0 ! Pod upravleniem BayRS u Nortel rabotayut tak zhe ASN i routery serii BN, ta chto, polagayu, i dlya nih podojdet. ===========================================================

7. TACACS,RADIUS,AAA

=========================================================== 7.1>Q: Gde vzyat' tacas-plus ? V ishodnikah ? >A: (Dmitriy Yermakov) Horom :)) ftp://ftpeng.cisco.com/pub/tacacs original'nyj original'nyj ot Cisco (ls tam ne rabotaet, snachala get README, potom get to, chto nuzhno) Nedavno tam byl - ls rabotaet. ftp://ftp.east.ru/pub/inet-admins - patchennyj na predmet raznyh vkusnostej ftp://ftp.vsu.ru/pub/hardware/cisco/tacacs - i eshche propatchennyj pppd teper' otdel'no ot tac+ia, no ryadom - tacpppd [08.09.2000] >A: (Igor Prokopov) Gde vzyat' TACACS+ pod NT ? http://www.nttacplus.com NTTacPlus2 (demoversiya dostupna dlya skachivaniya) Radius Tacacs+ Available for Windows NT 4.0 and Windows 95/98 Rabotaet s ODBC (Access97), preduprezhdaet e-mail'om ob okonchanii limita, mozhet byt' backup-serverom, rabotat' s neskol'kimi CISCO, vedet gruppy po privilegiyam i t.d. Polnaya versiya za den'gi ili na varezah ;))) 7.2>Q: Kto znaet, kak ogranichit' chislo zaprosov kiski na login? To est', esli yuzer pervyj raz nepravil'no otvetil na login/password to srazu sdelat' hangup a ne sprashivat' ego eshche i eshche. Vse ravno v bol'shinstve skriptov eto ne predusmotreno. U menya kiska uporno sprashivaet tri raza. Listanie "Command Summary" uspeha ne prineslo. Mozhet eto v takakse nado koncy iskat'? >A: (Alexey Kshnyakin) conf t; tacacs-server attempts N 7.3>Q: Kak snimat'/schitat' statistiku po interfejsam ? >A: (Dmitriy Yermakov) schitat' mozhno tak conf t int X ip accounting razreshit' rsh na kisku, primerno tak ip rcmd rsh-enable ip rcmd remote-host enable i, po kronu :) /usr/bin/rsh cisco clear ip accounting /usr/bin/rsh cisco sh ip accounting checkpoint > `/bin/date +"%Y%m%d%H%M"` /usr/bin/rsh cisco clear ip accounting checkpoint Poskol'ku voznikli voprosy, to eshche variant. >A: (Konstantin D. Myshov) 1) Skript: #!/bin/sh #[skip] rsh -l loger cisco.domain.adr clear ip accounting rsh -l loger cisco.domain.adr sh ip accounting checkpoint #[skip do konca skripta :-)] 2) Ha kiske govorish': username specloger privilege 8 password 0 plane_text_password ! Parol' zashifruetsya i cherez password 7 pokazyvat'sya budet po sh ru ip rcmd rsh-enable ip rcmd remote-host loger REMOTE_IP_ADDRESS REMOTE_USER_NAME enable 8 privilege exec level 8 show ip accounting checkpoint privilege exec level 1 show ip privilege exec level 8 clear ip accounting P.S. (Andrey Kuksa) kuksaa@chph.ras.ru vklyuchit' by eshche no ip rcmd domain-lookup P.P.S. (DY) Cisco proveryaet in-addr.arpa dlya hosta, s kotorogo prishel zapros na RSHELL. Esli IN PTR netu - ne puskaet. no ip rcmd domain-lookup etu proverku vyklyuchaet. Po umolchaniyu - vklyucheno. P.P.P.S. sm takzhe 0.4>Q: 7.4>Q: Kak zamenit' "Username:" na "login:" ? >A: (DY) Sushchestvuet 2 varianta - 1. V tac+ia mozhno pereopredelit' etot prompt. 2. aaa authentication username-promt [03.08.2000] 7.5>Q: rsh cisco show version poluchayu chto-to tipa Undefined error >A: (Alex Bakhtin) debug ip tcp rcmd [14.08.2000] 7.6>Q: ne rabotaet aaa authentication banner "..." pri ispol'zovanii tacacs ili radius dlya autentikacii >A: (Alexandre Snarskii), prislal (Vladimir Kravchenko) poprobovat' ispol'zovat' banner login "..." [08.09.2000] 7.6>Q: Probros na ifcico, raznye porty - raznye hosty. >A: (DY) zakryvaem temu ifcico. tacacs.conf group = fido { after authorization "/usr/local/tacplus/emsi $user $port" login = none service = exec { } } user = \*\*EMSI_INQC816 { member = fido } user = \*\*EMSI_INQC816q { member = fido } user = \*\*EMSI_INQC816\*\*EMSI_INQC816q. { member = fido } cat /usr/local/tacplus/emsi #!/bin/sh if [ "X$2X" = "Xtty3X" ] then echo noescape=true echo autocmd="telnet host_1 60179 /stream" else echo noescape=true echo autocmd="telnet host_2 60179 /stream" fi exit 2 [27.12.2000] 7.7>Q: Kak pri autentikacii na radiuse pol'zovatelyu naznachit' in-out ip access-list na ego interfejse ? >A: (Michael Korban) Framed-Filter-Id="blabla.in" Framed-Filter-Id="blabla.out" ===========================================================

8. Memory

=========================================================== [2000.10.12] 8.0> >A: (Alex Bakhtin) Ob容m pamyati, oppedelennyj IOSom pokazyvaetsya v vyvode komandy sh ver v vide dvuh chisel MEM1/MEM2, gde MEM1 - eto ob容m process memory a MEM2 - eto ob容m IO memory. p.s. (DY) for example 6144K/2048K - vsego 8Mb 126976K/4096K - vsego 128Mb 8.1>Q: A kakie simy mozhno stavit' v CISCO ? A to ya vse pepeppoboval, ni odin ne podhodit. :-( >A: (Vasily Ivanov) Ha simah dolzhny byt' ppavil'no paspayany pepemychki, ukazyvayushchie opganizaciyu sima i skopost' chipov v nanosekundah (bol'shinstvo kitajskih ppoizvoditelej eti pepemychki ne paspaivayut). Vot tablichka, kotopaya pomozhet vam eto sdelat': Razmep Opganizaciya 68 67 66 11 4Mb 512k*8/9 X X X X 4Mb 1M*2/4/16/18 - X X - 8Mb 2M*8/9 - X - X 16Mb 2M*8/9 X X - X 16Mb 4M*2/4/16/18 - X - - Hany 69 70 50ns X X 60ns - - 70ns X - Znakom [X] pomecheny kontakty, kotopye neobhodimo soedenit' s 72m kontaktom sima, obychno on vyveden uzhe v nepospedstvennoj blizosti ot pepemychek. [-] - svobodnyj kontakt. V nastoyashchee vpemya mozhno bez ppoblem kupit' 4h metpovye simy s opganizaciej 1M*2/4/16/18 i 16ti metpovye s opganizaciej 4M*2/4/16/18. 8mi metpovye simy so standaptnoj opganizaciej 1M*2/4/16/18 v putepah CISCO ne pabotayut !!! Takzhe kak i EDO RAM. NB !!! V 25hh simy bez papiteta _pabotat'_ne_budut_ ! Hikogda. >A: (Leonid Kirillov) Ot sebya dobavlyu malen'kuyu poproavku: 1. SIMM dolzhen imet' skorost' men'shuyu libo ravnuyu skorosti RAM na mamke; 2. Imeyutsya mamki 2 vidov: starye i novye. V staryh nuzhny SIMM s chetnost'yu, v novyh - net, tak kak eto vyklyucheno na mamke. Otlichie ochen' prostoe - ne zapayana pyataya mikroshemi pamyati. Gde ee iskat' - narisovano na kartinke: --------------------------------| | =======SIMM================== | | RAM1 RAM2 RAM3 RAM4 par | par | | Cisco 2501 3. Dvuhbankovyj SIMM viditsya kak odnobankovyj. Takim obrazom ya delal sebe 16Mb pamyati iz 32 (ochen' bylo nuzhno:-) Rabotaet normal'no. >A: (Kirill Osovsky) Eshche nemnogo o SIMM'ah. Dlya 1600 - chetnost' nezhelatel'na - rabotat' oni budut, no togda otvalitsya on-board DRAM. Dual bank 8 Mb viditsya i rabotaetsya kak 8 Mb Dlya 3620 - chetnost' (naskol'ko ya ponyal) bezrazlichna. Dual bank 8 Mb viditsya kak dual bank, no rabotat' 3620 s nim ne budet (ne polozheno po instrukcii) 3640 - rabotaet s dual bank. >A: (Dmitry Morozovsky) Eshche dopolnenie: 36xx rabotaet s EDO (3640 tochno, 3620. kazhetsya, tozhe). 3640 pri postanovke chetnogo kolichestva odinakovyh simmov perehodit v 64razryadnyj rezhim, chto uvelichivaet proizvoditel'nost', no takzhe uvelichivaet i rashod pamyati v svyazi s alignment. P.S. (Basil Dolmatov) 3620 ponimaet tol'ko FPM. 3640 ponimaet i EDO tozhe. 8.2>Q: Podskazhite gde eshche vstrechayutsya eti 100-pinovye DIMM'y, kotorye v 2600 stoyat. Ili gde ih mozhno kupit'? Za dve tonny baksov ne predlagat'. >A: (Dmitry Morozovsky) Podhodit pamyat' dlya HP LJ 4000 (100pin EDO SODIMM). Krome togo, mozhno brat' pamyat' u prakticheski lyubogo dilera Micron, Transcend, Kingston. U etih -- prosto po katalogu. P.S. |to zhe otnositsya i k MC3810. [04.07.2000] 8.3>Q: A ne podskazhet li kto-nibud', kakaya SIMM-pamyat' podhodit k serii 4000 (konkretnee, 4500M+) i chego na nej propayat'? Imeetsya v vidu: edo/fpm, chetnost', paritet, chislo chipov. >A: (Alexander Voropay) Dlya 4500 podhodit ta zhe samaya pamyat', chto i dlya 2500, i FLASH i DRAM. Packet DRAM ta zhe samaya, chto i System DRAM, i chem bol'she tem luchshe :-) A konkretno, 72-pin SIMM, NoEDO (FPM), real Parity. Obyazatel'no dolzhny stoyat' peremychki ID. Luchshe brat' -60ns hotya dlya System DRAM podojdet i -70ns. ===========================================================

9. NTP, TZ

=========================================================== 9.1>Q: Kak pravil'no vystavit' timezone i sinhronizirovat' vremya na kiske >A: (Vasily Ivanov) vot ppimep dlya Omska (UTC+6): clock timezone OMT 6 clock summer-time OMTS recurring last Sun Mar 3:00 last Sun Oct 3:00 I eshche: 1) chasy ustanavlivayutsya, esli tol'ko na tajm-sepvepe vpemya vystavleno koppektno, esli zhe on nahoditsya v ppocesse podvedeniya svoih chasov, to ciska budet zhdat' okonchaniya etogo ppocessa. 2) vystavlenie chasov ppoishodit ne spazu, a 5-10 minut. Podozhdi nemnogo. >A: (Alec Voropay) dlya Moskvy clock timezone MSK 3 clock summer-time MSD recurring last Sun Mar 2:00 last Sun Oct 3:00 9.2>Q: A kak zastavit' kisku sinhronizirovat' vremya s kakim-libo serverom i byt' samoj ntp-serverom ? >A: (Maksim Malchuk) ntp source interfaceX ntp master 3 ntp server aaa.bbb.ccc.ddd ntp server eee.fff.ggg.hhh ntp server iii.jjj.kkk.lll P.S. (Alex Bakhtin) ntp master 3 - eto znachit, chto esli ppopadut vse ntp servers, kotopye ppopisany v konfige, kiska budet schitat' sebya sepvepom so stratum 3. P.P.S. (Sergey Romantsov) Ntp master - ukazyvaet, chto router yavlyaetsya odnim iz istochnikov "tochnogo" vremeni, poetomu esli neobhodimo chtoby on razdaval vremya drugim ustrojstvam, neobhodimo ego ob座avit' kak master s sootvetstvuyushchej velichinoj stratum. stratum=1 : eto atomnye chasy stratum=2 : ustorjstvo neposredstvenno podklyucheno k atomnym chasam stratum=3 : ustrojstvo svyazano s ustrojstvom ( sm vyshe) i tak dalee... do 15. stratum=16 : ustrojstvo ne yavlyaetsya avtorizovannym istochnikom vremeni. ===========================================================

10. NAT

=========================================================== 10.1>Q: Mozhno kak-nibud' sdelat' na kiske 2511 s IOS 11.3, chtoby vse soedineniya po FTP, WWW s lokal'noj setki (imeyushchej public internet adresa) ustanavlivalis' s adresa skazhem 62.244.63.114, eto svyazano s tem, chto pri ustanovlenii soedineniya s etogo adresa pakety vozvrashchayutsya cherez sputnik. >A: dimka@spy.ints.net (Dmitry Aksyonov) tochno dlya etogo sluchaya: [..] ip nat inside source list 111 interface Loopback4 overload [..] interface Loopback4 ip address 62.244.63.162 255.255.255.255 [..] interface Ethernet0 ip nat inside [..] interface Serial0 ip nat outside [..] access-list 111 permit tcp 194.44.58.0 0.0.0.255 any eq ftp access-list 111 permit tcp 194.44.58.0 0.0.0.255 any eq ftp-data access-list 111 permit tcp 194.44.58.0 0.0.0.255 any eq www ostal'nye porty po vkusu ;) posmotret' chto poluchaetsya - sh ip nat tra 10.2>Q: Est' dve setki: 192.H.H.0 i 193.H.H.80/28 i kiska 2509 Huzhno vklyuchit' NAT, chtoby yuzera iz 192... setki hodili v 193... . Interesuet kusok(ki) konfiga kiski, tol'ko rabotayushchij i podrobnyj. >A: (Eugene A. Rakhmatulin) Hizhe kusok real'no rabotayushchego konfiga (izmeneny tol'ko IP): est' set' 193.193.193.224/29, kotoruyu dal provajder i vnutrennyaya set' 192.168.1.0/24. Ha translyaciyu vseh vnutrennih adresov, krome 192.168.1.2 vydelyaetsya adres 193.193.193.227, a na 192.168.1.2 zapisyvaetsya staticheskaya translyaciya adresa 193.193.193.230. cs-2501# show running-config [ .. ] ip nat pool one 193.193.193.227 193.193.193.227 netmask 255.255.255.248 ip nat inside source list 1 pool one overload ip nat inside source static 192.168.1.2 193.193.193.230 [ .. ] ! interface Ethernet0 ip address 192.168.1.1 255.255.255.0 ip broadcast-address 192.168.1.255 ip nat inside [ .. ] ! interface Serial1 description Link to Provider ip address 193.193.193.226 255.255.255.248 ip nat outside [ .. ] access-list 1 permit 192.168.1.0 0.0.0.255 10.3>Q: Provajder vydal odin real'nyj adres (vmesto byvshego ranee bloka adresov) i nuzhno v techenii perehodnogo perioda (3 dnya) operativno perenastroit' Cisco 2509 dlya marshrutizacii v sleduyushchej konfiguracii: Ethernet - soedinyaetsya napryamuyu edinstvennym real'nym adresom s marshrutizatorom provajdera; Serial1 - smotrit (cherez vydelenku) v odnu fizicheskuyu set'(~20 komp'yuterov+programmnyj marshrutizator); Serial2 - smotrit v druguyu(~10 komp'yuterov). >A: (Ilya Geldiev) ip nat translation timeout 1800 ip nat translation tcp-timeout 1800 ip nat translation udp-timeout 150 ip nat inside source list 101 interface Async8 overload ' ip nat inside source static tcp {Ethernet0-ip} 80 {Async8-ip} 80 extendable ' ne bolee chem probros veb-zaprosov vo vnutrennyuyu LAH ! interface Ethernet0 description connected to internal LAN ip nat inside ! interface Async8 description connected to ISP ip nat outside ! interface Async9 description connected to internal Remote Access dialer-group 1 ! interface Group-Async1 description connected to Dial-inPCs_mobile ip nat inside ! 10.4>Q: Vpustit' obratno s Inet-a v lokalku. Skazhem dlya pochty -- moj ciskovskij adres s portom 25 probrosit' v lokal'nyj segment na moj pochtovik ? >A: CoreDumped@CoreDumped.null.ru ip nat inside source static tcp int.ter.nsl.addr 25 ext.ter.nal.addr 25 extendable no-alias ===========================================================

11. Telco, ISDN

=========================================================== [20.10.2000] 11.0> Razborki s ISDN Layer 1,2. Kompilyaciya neskol'kih voprosov i otvetov. (Gosha Zafievsky) Voobshchem vse smotret' po doke. Cisco po umolchaniyu vstaet kak user-side device. Esli Layer 1 not UP - proverit' _doskonal'no_ vse kabeli i soedineniya, smotret' sh controller e1 XX na predmet nalichiya oshibok. Oshibki mogut voznikat' tol'ko v sluchae nepopadaniya v ustanovki crc/no-crc, drugie varianty vstrechayutsya krajne redko. Kak tol'ko oshibki na kontrollere propadut, Layer 1 obychno stanovitsya ACTIVE. Vystavit' pravil'no isdn switch-type Esli Layer 2 TEI_ASSIGNED - vystavit' pravil'no network side, dolzhno byt' MULTIPLE_FRAME_ESTABLISHED, ne ver'te na slovo telefonistam :) Esli s drugoj storony tupoe zhelezo, ne umeyushchee NETWORK-SIDE, postavit' IOS 12.1.3T - tam poyavilos' isdn protocol-emulate network Kak tol'ko Layer 2 MULTIPLE_FRAME_ESTABLISHED - vse dolzhno rabotat'. V klinicheskih sluchayah ne podnyatiya Layer 2 - deb isdn q931 na bochku blizhajshemu guru. 11.1>Q: AS5300 i Ericsson MD-110. >A: (Aleksey Fedorov) U menya AS5300 podklyuchena k Ericsson AXE-10 po r2-digital. V moem sluchae chtoby vse bylo horosho nuzhno skazat': cas-custom 0 debounce-time 10 seizure-ack-time 10 country itu use-defaults >A: (DY) rabotaet vot tak, no so stanciej dolgo muchalis'. controller E1 1 clock source line secondary 1 pri-group timeslots 1-31 ! interface Serial1:15 isdn switch-type primary-net5 isdn incoming-voice modem isdn bchan-number-order ascending isdn sending-complete ! 11.2>Q: 2610 nikak ne hochet zvonit' na Definity, pri zvonke s Definity BRI podnimaetsya i srazu padaet. >A: (Gosha Zafievsky) Ha kiske isdn switch-type basic-net3, v Definity etot BRI nado opisat' kak data module ili trunk, no ne kak WCBRI station. Country protocol : etsi. 11.3>Q: isdn caller number, AS5300, Alcatel S12, ISDN PRI. >A: "Victor L. Belov" interface Serial0:15 isdn switch-type primary-net5 isdn protocol-emulate user isdn incoming-voice modem isdn sending-complete i oni prihodyat. ios 12.0.4-XH [13.06.2000] 11.4>Q: Imeem 3640 - E1R2 - AXE 10. >A: (Vladimir A. Golovnin) > controller E1 0/0 > framing NO-CRC4 > ds0-group 0 timeslots 1-15,17-31 type r2-digital r2-compelled > cas-custom 0 > debounce-time 10 > seizure-ack-time 10 > dnis-digits min 1 max 2 > ani-digits min 3 max 6 > description First E1 line : connected to port 1 U menya nastroeno tak: controller E1 0/0 framing NO-CRC4 ds0-group 0 timeslots 1-15,17-31 type r2-digital r2-compelled cas-custom 0 country easteurope debounce-time 10 release-guard-time 150 seizure-ack-time 2 dnis-digits min 1 max 3 ani-digits min 0 max 3 answer-guard-time 40 ani-timeout 1 Vrode rabotae, no kriven'ko kak to. Rabotalo eshche krivee kogda seizure-ack-time = 8, a pri 10 i vyshe vooshche trubku ne brala. P.S. (Gosha Zafievsky) VG> country easteurope Vot s etim - poakkupatnee. YA by dlya nachala postavil country itu use-defaults. R2MFC v Cisco - veshch' v sebe... 11.5>Q: Voznikla sleduyushchaya neobhodimost' - svyazat' po ISDN dve zhelezki - Zyxel Prestige-100 (eto ISDN-router takoj) i Cisco 2522CH. Sovershenno ne poluchaetsya eto sdelat'. Zvonit' dolzhen Zyxel etot samyj, nu tak on zvonit, udalos' dazhe dobit'sya authentification po protokolu pap, no protokol ne podnimaetsya. YA tak ponimayu protokol dozhen podnyat'sya na BRI0:1 ili BRI0:2, a ona ne daet ih konfigurit' po otdel'nosti, a esli skazat' chto-to pro LeasedLine - to ne otvechaet na zvonki. Kak i chto nado ej skazat', chtoby poluchit' ot etogo Zyxelya 64 ili 128 K po DialAp - ISDN ? >A: (Mark Gorovenko) Protokol budet podnimat'sya na Virtual-Access Kusochek iz podobnogo konfiga privedu. V nem mnogo lishnego, bylo sdelano dlya togo chtoby mozhno bylo zvonit' v raznye mesta, eto mozhno vykinut'. interface Virtual-Template1 ip unnumbered Ethernet0 no ip directed-broadcast autodetect encapsulation ppp peer default ip address pool default no fair-queue ppp authentication chap pap callin ppp multilink ! interface BRI0 ip unnumbered Ethernet0 encapsulation ppp no ip route-cache bandwidth 128 dialer pool-member 1 autodetect encapsulation ppp isdn incoming-voice modem 64 isdn answer1 xxx isdn answer2 xxx isdn calling-number xxx peer default ip address pool default no cdp enable ppp authentication chap pap callin ! interface Dialer0 ip address xxxx encapsulation ppp bandwidth 64 dialer remote-name xxx dialer idle-timeout 30 dialer string xxx dialer load-threshold 1 either dialer pool 1 dialer-group 1 autodetect encapsulation ppp v120 peer default ip address xxx no cdp enable ppp authentication chap pap callin ! interface Dialer1 ip unnumbered Ethernet0 encapsulation ppp bandwidth 64 dialer remote-name xxxx dialer idle-timeout 30 dialer wait-for-carrier-time 15 dialer string xxxxx dialer load-threshold 1 either dialer max-call 4 dialer pool 1 dialer-group 2 peer default ip address xxx no cdp enable ppp authentication chap pap callin ! ip local pool default xxx ip classless ip route 0.0.0.0 0.0.0.0 xxxxx ip route xxxxxxxx 255.255.255.255 Dialer1 ip route xxxxxxxx 255.255.255.255 Dialer0 access-list 11 permit any access-list 100 permit ip any host xxxxxx virtual-profile virtual-template 1 dialer-list 1 protocol ip list 11 dialer-list 2 protocol ip list 100 =========================================================== 13. SNMP =========================================================== 13.1>Q: Rebut kiski po snmp ? >A: (Oleh Hrynchuk) snmp-server system-shutdown and after that.... snmpset -c community -t 70 ip.addr.of.router .1.3.6.1.4.1.9.2.9.9.0 i 2 13.1>Q: Download cisco config via SNMP. >A: Prislal (Oleh Hrynchuk) Using SNMP and the appropriate OID .1.3.6.1.4.1.9.2.1.55, postfix the IP address as the index for the OID. Use this "OID" as a string set value. The string value will be the name of the file. snmpset .1.3.6.1.4.1.9.2.1.55.10.10.20.20 string "" The router will reward you with a nice log message and the file should appear on the tftp server (in this example, 10.10.20.20). Be careful as some UN*X tftp servers will not create files, but can only write to existing files (little security precaution). A much more interesting exercise is to get a router to read a config from a tftp server using only snmp...but we'll cover that some other time. Tod Daniels Greymatter, Inc. [17.01.2001] >A: (Joe Hishon) I use a UNIX shell script. You need to have a tftp server also running. For example if your tftp server is at 192.168.1.1, and your target router is IP "$IP" and read-write community "$RW" then the important lines are: 'wr mem' snmpset -c $RW $IP .1.3.6.1.4.1.9.2.1.54.0 integer 1 'wr net' snmpset -c $RW $IP .1.3.6.1.4.1.9.2.1.55.192.168.1.1 octetstring routername-confg for COS switches... 'wr net' snmpset -c $RW $IP .1.3.6.1.4.1.9.5.1.5.1.0 octetstring 192.168.1.1 snmpset -c $RW $IP .1.3.6.1.4.1.9.5.1.5.2.0 octetstring routername-confg snmpset -c $RW $IP .1.3.6.1.4.1.9.5.1.5.4.0 integer 3 =========================================================== 14. Cables =========================================================== 14.1>Q: Slyshal, chto est' kabel' dlya soedineniya dvuh cisok DB60M <-> DB60M no nigde na cisco.com ne smog ego najti ? >A: (Yuri Yuferev) http://www.pacificable.com/PicFrames/CABMMXHD60PicFrame.htm? =========================================================== 15. TROUBLESHOOTING =========================================================== ty sobiraesh'sf "eto" lechit'??? :) pokazyvat' nado - "sho mem" ;) v FAQ nado pisat', chto pamyat' libo konchilas', libo otfragmentirovalas'.. :) lechit' mozhno raznymi sposobami, v zavisimosti ot real'noj prichiny... nachinaya ot banal'noj dobivki pamyati ili vyklyucheniya yaunkcij, kotorye dannyj koshak s dannoj pamyat'yu ne tyanet, prodolzhaya optimizaciej funkcij, zhrushchih pamyat' s primeneniem golovy, i zakanchivaya smenoj IOS na tot, v kotorom ... dannyj konkretnyj memory leak ustranen (ili eshche ne vnesen :) I/O mem v 25-j serii _vsegda_ 2 mega... :) ===========================================================

97. Software

=========================================================== Zdes' ssylki na razlichnyj soft dlya Cisco i ne tol'ko. Nekotorye mogut dublirovat'sya iz drugih razdelov. Accounting ipaccounting ipanalize ipacc from ss23 Yura Pismerov http://www.mcs-cityline.net/~lf/ctm/ http://www.ts.infn.it/computing/IPaccounting/ http://linux.uatel.net/soft/iptrafsnmp/iptrafsnmp.phtml NetFlow [27.12.2000] http://www.auckland.ac.nz/net/NeTraMet http://www.caida.org/Tools/Cflowd IPMeter OSU flow-tools NFC/java by John Gladkih MONITORING mrtg rrdtool ROUTING GateD Konfigi - snapshot GNU Zebra mrt TACACS,RADIUS [27.12.2000] ftp://ftpeng.cisco.com/pub/tacacs original'nyj origina l'nyj ot Cisco ftp://ftp.east.ru/pub/inet-admins ftp://ftp.vsu.ru/pub/hardware/cisco/tacacs http://www.nttacplus.com - TACACS for NT cistron livingston merit freeradius xtradius radius by vl TUNNELs [27.12.2000] for FreeBSD (prosto kak-to nashel) ftp://ftp.sut.ru/pub/dyer/tunnel (nos-tun est' v samoj sisteme) (Alexander A. Karpoff) - http://mike.spottydogs.org/projects/gre-tun TOOLS dialout subnet calculator tftpd for !nix ===========================================================

98. IOS Black List/White List/Recommendations

=========================================================== [14.06.2000] 12.0(5)Tx. Dobpyj sovet. Vykin'te eto ono dlya ispol'zovaniya _sovepshenno_ ne ppigodno. Alex Bakhtin [15.06.2000] 3640 12.0(4)T - CEF glyuchnyj. Sil'no. Dmitri Kalintsev [05.09.2000] Vladislav Nebolsine 12.1 (bez bukovki) - eto proverennaya i obkatannaya 12.0T (s bukovkoj), v kotoruyu pereshli vse ee fichi. A v 12.1T (s bukovkoj) dobavleny novye fichi (i podderzhka novyh platform), kotorye so vremenem perejdut v 12.2. Est' fichi, kotorye ne voshli v 12.1, tak kak byli ne v 12.0T, a v 12.0XK. Haprimer, podderzhka Q.SIG, kotoraya byla v 12.0(5)XK i 12.0(7)XK), pereshla ne v 12.1(1), a v 12.1(2)T. I eshche ryad fich iz razlichnyh ne-T imadzhej. Vybirat' nado po potrebnostyam (i razmeru flesha) i nalichiyu trebuemyh fich v imadzhe. Perechen' fich v kazhdoj versii est' v dokumentacii na www.cisco.com: http://www.cisco.com/univercd/cc/td/doc/product/index.htm 12.1(2a) - horoshaya rabotayushchaya versiya IOSa s polnocennoj podderzhkoj golosa. Ne pomnyu kto soobshchal. 12.1(3)T - raznye SNMP indeksy na sub-if VLAN/ISL. -is- - uzhe ne lezet v 8Mb Flash Basil (Vasily) Dolmatov - Mmm... YA ne stal by pol'zovat' IRB v rannih versiyah 11.2 mainline ;) [17.01.2001] Vladislav Nebolsine. Samyj stabil'nyj _golosovoj_ IOS na segodnyashnij den' - 12.1(3a)XI5 [17.01.2001] v 90% softa 12.1(x)T na 7206VXR ne rabotaet export netflow ===========================================================

99. Misc

=========================================================== 99.1>Q: Kak poslat' kiske break ? 03 eto skoraya, 02 - miliciya, a break - eto ne simvol, a ochen' dlinnyj start-bit (c) Michael Shestyriov >A: (DY) RTFM po terminalke :) cu,tip - ~#, ~% DOS Navigator - F4 >A: (Alec Voropay) http://www.cisco.com/warp/customer/701/61.html 99.2>Q: Kak vosstanovit' zabytyj (ne mnoj, a administratorom) parol' ili smenit' ego na kakoj-to drugoj? Mozhno li sdelat' eto bez poteri konfiguracii? >A: (Gosha Zafievsky) RTFM, konkpetno User Guide, eshche konkpetnee "Recovering a lost enable password". Da. P.S. (DY) pro Break - sm. vyshe >A: (Alec Voropay) http://www.cisco.com/warp/customer/701/22.html [25.07.2000] >A: (Konstantin Gribakh) Cisco sobrala vse eti procedury na odnoj stranichke http://www.cisco.com/warp/public/474/index.shtml 99.3>Q: Sertificirovano li v Minsvyazi oborudovanie Cisco ? >A: (Serge Turchin) Da, nomera sertifikatov OS/1-SPD-59 - OS/1-SPD-91 http://www.amt.ru/products/cisco/certificates/index_tmp.phtml >A: (Denis Golovenko ) OS/1-SPD-70 -- dlya modelej 2505/07/09/11/18 >A: (Vladislav Nebolsine) CIIIS bylo sertificirovano sleduyushchee oborudovanie: Marshrutizatory Cisco 761, 765, 771, 775 1001, 1003, 1005, 1601, 1603 2501, 2503, 2505, 2507, 2509, 2511, 2512, 2514, 2518, 2520, 2522 26xx 3620, 3640 4000, 4000M, 4500, 4500M, 4700, 4700M 7204, 7206, 7505, 7507, 7513 AS5200, AS5300 MC3810 Cache Engine LDIR-410, LDIR-420 LAN kommutatory Catalyst 1400, 1900, 2820, 29xx 3000, 3100, 3200 5000, 5002, 5500, 5505 WAN kommutatory LightStream 1010 IGX8, IGX16, IGX32, IGX8410, IGX8420, IGX8430 BPX8600 MGX8220 Setevye ekrany Cisco PIX Firewall (3 klass zashchishchennosti po sisteme sertifikacii sredstv zashchity informacii po trebovaniyam bezopasnosti informacii) P.S. (DY) Spisok sootvetstviya oborudovaniya i sertifikatov http://www.comptek.ru/cisco/teach/certif.html [05.01.2001] >A: Ilia Zubkov - pro sertifikaciyu Catalyst Na etu temu -- vot u menya na stole lezhit kopiya pis'ma zam. ministra MinSvyazi Volokitina (b/n, ot 02.11.2000) v moskovskij ofis kiski o tom, chto, mol, "Na Vash zapros o neobhodimosti sertifikacii kommutatorov" tipa Catalyst 1900,2900XL,3500XL,4000,6000,8500CSR "Minsvyazi soobshchaet, chto ukazannoe oborudovanie ne podlezhit sertifikacii v sisteme "|lektrosvyaz'", i ego primenenie ne zapreshchaet kommercheskuyu ekspluataciyu seti pri ustanovke na uzlah svyazi dlya soedineniya oborudovaniya vo vzaimouvyazannoj seti po protokolam Ethernet, FastEthernet, GigabitEthernet". Po moemu razumeniyu, zhelayushchim v MinSvyazi ne dolzhny otkazyvat' v vydache kopii etogo pis'ma. P.S. (DY) poskol'ku eto pis'mo b/n (bez ishodyashchego nomera) to status etogo pis'ma do konca ne yasen. [13.06.2000] 99.4>Q: Kak po nazvaniyu fajla oppedelit' vepsiyu iosa, IP-only on, IP/IPX ili enterprise? >A: (Serge Turchin) *-i-* - IP *-is-* - IP Plus *-d-* - Desktop *-ds-* - Desktop Plus *-j-* - Enterprise. i t.d. V 11.2 net IP/IPX, a tol'ko Desktop, na nego cena snizhena v sravnenii s 11.1. Suffiks - a - appn. Voobshche, gde-to est' na servere rasshifrovka. U 1000-nyh yader sistema drugaya. n-Novell, b - Apple Talk, y - IP, q - asinhronnyj variant. > I eshche - na sajte dlya vepsij byli fajly pazmepom v 2-4paza men'she iosov i > s > zagadochnym slovom boot v nazvanii - eto bootstrap only? :-) U 7500, 4500-4700 net proshityh namertvo butovyh sistem. Ho est' special'nyj t.n. bootflash v kotorom zapisana ukorochennaya versiya sistemy. >A: (Dmitriy Yermakov) Kazhetsya vse opisano tut - http://www.cisco.com/warp/public/620/1.html 99.5>Q: Est' li podderzhka R2 dlya 3600 ? >A: Vladislav Nebolsine ***Hot News*** Announcing R2 support for the 3600 Digital Modems!! Hot News!!! =========== Announcing R2 support for the 3600 family of Digital Modems ================================================= The 3600 team is pleased to announce R2 support for integrated Digital Modems on the popular Cisco 3600 series platform. This feature is available with the introduction of IOS 12.0(1)T This new feature supports the use of R2 signalling with the 3600 internal digital modems, enabling high-speed (up to 56kbps) remote access for branch offices and small/mid size ISP's who utilize this specific line-signalling protocol. This announcement extends the range of connectivity options available for the 3600 Digital Modems, now supporting: PRI CAS(CT1) R2 (CE1)) By supporting this flexible range of signalling protocols , the 3600 digital modem solutions can now be deployed on a world-wide basis! A Country list and Mini Q&A follow. Countries configurable with R2 on the 3600: (this is a subset of the supported 5300 R2 countries) ================================= Argentina Australia Brazil * China * Columbia Costa Rica Eastern Europe mode supports: Croatia Russia * Ecuador (ITU and LME) Greece Guatemala Hong Kong (China & ITU Variants) India Indonesia Israel * ITU mode supports: Denmark Finland Germany Russia (ITU variant) * Hong Kong (ITU variant) South Africa (ITU variant) Korea * Malaysia * Mexico (Telmex and Telnor) * New Zealand * Paraguay Peru Philippines Saudi Arabia Note: All countries listed have been tested in house. Countries marked with a * have also been successfully tested in-country. Mini Q&A ========= Q. What is R2 ? A. R2 is a signaling system (Q.422) used by a number of countries worldwide. This signaling system runs over an E1 Carrier (2.048Mb/s), containing 32 64Kb/s timeslots, of which, 30 timeslots can be used for digital modem calls. Q. Does this feature require new hardware in the 3600? A. No Q. What network modules support this feature? A. All the current 1/2 PRI NMs, including the new 1FE 1/2 PRI NM. Q.Is the Cisco Dial-out Utility supported through an R2 connection? A. Yes. Version 2 of the Cisco Dial-out Utility (available early November) together with MICA Portware 2.5.1.0 support Dial/Fax out through the R2 interface Q. Is this R2 feature supported the Cisco 2600, 3620, and 3640? A. The ability for Modem calls to be terminated through an R2 interface is available for all platforms that support Cisco digital modems. This currently limits R2 support to the 3640/3620 Q. Do I need a new version of the digital modem microcode to support R2? A. No. All shipping versions of Portware are supported. For information on Portware and instructions on downloading the latest version, please visit: http://www.cisco.com/public/sw-center/sw-access.shtml. Q. What IOS is required to utilize this feature? A. IOS 12.0(1)T and above Q. Can I support ISDN PRI R2, and CAS in the same chassis? A. Yes, on a per network module basis. Each individual PRI NM can be configured as R2,CAS or ISDN PRI. Q. What countries will this R2 feature be available in? A. At FCS, a subset of the 5300 supported R2 countries will be supported. All Countries in the list above have been successfully tested internally. Q. Will the new mixed media FE/PRI support R2? A. Yes. Q. Can two PRI/R2 links share one DM NM? A. Yes. The pool of modems is available to all R2/PRI interfaces. 99.6>Q: Kogda zhe nakonec budet reliz V.90 dlya MICA ? >A: (Oleg Zharoff) Vyshel nakonec dolgozhdannyj reliz V.90 dlya MICA modemov, versiya 2.5.1.0. http://www.cisco.com/univercd/cc/td/doc/product/access/acs_serv/5300/ mod_info/53fw_pw/53micaa/rn250x.htm 99.7>Q: A vot pochemu ya ne mogu cherez console zajti na moyu ciscu? I nastrojki krutil, i porty na mashinkah zhivye, a chto ne tak - ne pojmu. >A: Pavel Stepchenko McFlySr@irc Prover'te marku vashej motherboard. Esli eto Atrend, prover'te, "rodnye" li "kosichki"? Delo v tom, chto poganye(kto mne vozmestit dushevnoe ravnovesie?! ;) ) kitajcy reshili, chto oni umnee vseh, i zayuzali "kosichki" s shahmatnoj raspajkoj(kak i na AT486); na ostal'nyh zhe MB - pryamaya raspajka. Esli ne ATREND - vse ravno prover'te porty na celostnost', tak kak cu po umolchaniyu imeet Xon/Xoff i voobshche :) Ubezhdaemsya, chto na cuaa0(1) ne visit (m)getty, puskaem cu -l /dev/cuaa0(1), i naslazhdaemsya zhizn'yu :) Thanks for support: CGHost, Fifo, Jimson, Lee7, Mdh, ReedCat, vul. 99.8>Q: Tut problema - kto znaet kak vystavit' nomer seti u Hovell'nogo klienta ? Hachal bit' setku na VLANy - i voznikli problemy. MS rabotaet normal'no, a Hovel'nyj klient ne hochet. >A: (Serge Turchin) Propisat' spantree portfast na portah Katalista. [13.06.2000] 99.8.1>Q: Kak zastavit' porty na 2924XL bystree inicializirovat'sya ? >A: os@alkar.net http://www.cisco.com/warp/public/473/12.html 99.9>Q: Kto-nibud' znaet, kak byt' s uteryannym parolem na 1020? >A: (Gleb Pijov) Question: How do you recover lost passwords on a Cisco 1020? Answer: As the Cisco 1020 is rarely physically secured, password recovery is done by calling Cisco and providing a system generated CHALLENGE. Using the override program, the support engineer can provide a one-time password to use to get into enable mode. Then, follow these steps: 1.Customer: Put up dip switch 1 and apply power. You should see "Console Username:". 2.Customer : Login with Username "enable" and Password "override". It will print a CHALLENGE. 3.Cisco runs the override program and prints a RESPONSE. 4.Customer: On the 1020, log in as "enable" and give the RESPONSE as the password. That will get you the # prompt, then you can do a wr t to see the current enable password. Or, you can do a config t and reset the enable password. 99.10>Q: Problemy s MTU na interface tunnel. >A: "Philipp V. Patrushoff" BugID: CSCdm54169 >>> [13.09.2000] Vladislav Nebolsine, NB !!! >>> bag ispravlen v 11.3(11) i 12.0(6) You cannot change the MTU size of a tunnel interface using software after Cisco IOS Release +11.3(9.2). Workarounds: Use images between Release 11.3(5.1)T and Release 11.3(9.3) or Release 12.0(0.16) and Release 12.0(4.2). Configure ip mtu on the tunnel interface before you configure tunnel destination. If tunnel destination is already configured, then unconfigure the destination, configure ip mtu, and then reconfigure the destination. You need to wait five seconds after removing the tunnel destination before issuing the ip mtu command. Once the workaround is issued, there should be no problems in the event of a router reboot as the ip mtu command is parsed before the tunnel destination. [27.12.2000] 99.11>Q:Est' neskol'ko Kisok sepii 25xx. Hyzhno odnovpemenno na vseh v oppedelennyj moment menyat' X25 routing, ppichem zhelatel'no odnim skpiptom iz-pod FreeBSD. Kak ? >A: A: (Alex Bakhtin), (John Gladkih), (Vladislav Staroselsky) === newconfig === interface serial shutdown exit no x25 route ... x25 route ... interface serial no shutdown end === newconfig === === Cisco config === ip rcmd rcp-enable ip rcmd remote-host enable ip rcmd remote-username rlogin trusted-remoteuser-source local rlogin trusted-localuser-source local === Cisco config === === change_routing.sh === #!/bin/sh su -c "rcp newconfig @:running-config" === change_routing.sh === V newconfig vstavlyaem nyzhnye izmeneniya tekyshchego poytinga (chepez no route i route). Ppopisyvaem na FreeBSD yuzepa. V nyzhnyj moment zapyskaem change_routing.sh ===========================================================

NN. Zametki na polyah.

=========================================================== Sergey Trofimovsky - PPP per-user timeouts explained http://www.employees.org/~dpeng/per_user_timeout.htm Kstati govorya, nachinaya s 11.3(8)T (ili AA :-) timeouts uzhe i v PPP/PAP rabotayut.Bez izvratov v vprofiles etc. Dmitriy Yermakov - gde-to nachinaya s 11.3(5)T poyavilos' ppp authorization per interface teper' mozhno otklyuchat' avtorizaciyu na leased line s enc ppp Serge Turchin - V 12.03T poyavilsya X.25 over FR... Vladislav Nebolsine - Hu, a podrobnee ob etoj opcii mozhno prochitat' zdes' http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/120newft/120t/120t3/x25anxg.htm Dmitriy Yermakov - trebovaniya k ob容mu pamyati http://infoblast.comptek.ru/cpqrg/cpqrg2.htm#xtocid2097032 Cisco-on-line Conference on Comptek http://online.comptek.ru/cisco/index.html Martin McFlySr Cisco Year 2000 Product Compliance URL http://www.cisco.com/warp/public/cc/cisco/mkt/gen/2000/prodlit/cptbl_ov.htm Dmitriy Yermakov - Problemy s Zelax M115 na svyazke cisco-unix, reshenie ot Igorya Nikolaeva - http://knot.pu.ru/faq/pppd.html Raspajki razlichnyh kabelej, konfigi dlya modemov - http://www.links.ru [13.06.2000] Cisco IOS Software RoadMap - http://www.cisco.com/warp/public/620/roadmap.shtml [13.06.2000] Vasily Ivanov - Ogranichenie skorosti konnekta dlya MICA modemov - http://www.cisco.com/univercd/cc/td/doc/product/access/acs_serv/5300/mod_info/at/atcmnds.htm [04.07.2000] Vladislav Nebolsine - Esli komu interesno - v 12.1(2)XH poyavilas' - podderzhka E1 R2 dlya 2600/3600/7200, - Caller ID dlya 3810/2600/3600, - ISDN PRI Q.931 User-Side/Network-Side dlya golosovyh modulej 2600/3600 (do etogo byl tol'ko Q.SIG) - i koe-chto drugoe. Podrobnosti: http://www.cisco.com/univercd/cc/td/doc/product/software/ios121/121newft/121limit/121x/121xh/121xh_2/index.htm [04.07.2000] Poltergejst v NM-*AM (Problemy s NM-8AM (NM-16AM)) Simptomy: 1. Modemy ne berut trubu pri vhodyashchem zvonke. 2. Modemy pokazyvayut nalichie vhodyashchego zvonka prosto pri podklyuchenii k tel.linii. 3. Pri zvonke obratnym telnetom na obychnyj telefon - vmesto handshack-signala - rev 50 gc. Zazemlite cisku. [27.12.2000] Yuri Vorobyev - Cisco ground http://www.cisco.com/univercd/cc/td/doc/product/access/acs_mod/cis3600/3600_ cn/nebslugs.htm [02.08.2000] Gosha Zafievsky NM-8AM, NM-16AM _ne_ podderzhivayut rezhim leased line. P.S. (DY) ZHelayushchie mogut poeksperimentirovat' s ATA i bol'shIm vremenem ozhidaniya CARRIER. Za rezul'tat ne ruchayus'. [12.09.2000] john gladkih - LL na MCOM modemah (NM-8/16AM) kogo interesovali LL na MCOM modemah? ono rabotaet. my zavodili 18 vol't na korotkoj linii. cherez DDR+RIP [05.09.2000] Victor L. Belov - Tunnel' s win98 na cisco router variantov 2 =-) 1. pptp podderzhivaetsya tol'ko v special'nom IOS (12.0.7XE chto li... ne pomnyu tochno) na 7xxx marshrutizatorah. S drugoj storony pptpd na FreeBSD i Linux rabotaet normal'no. 2. na melkih marshrutizatorah podderzhivaetsya l2tp tunneli, no togda na 95/98/NT pridetsya stavit' dop. klient - naprimer WinVPN ot http://www.routerware.com V Windows 2000 est' vstroennaya podderzhka l2tp. YA dazhe zavel mezhdu nim i Cisco IPSec - poluchaetsya sovsem horosho. [22.10.2000] (DY) psevdovydelenka na chem ugodno, kak podnimat' kanal. Kak nastraivat' DDR - chitat' doki. A chtoby kiska sama podnimala kanal ne zavisimo ot aktivnosti v seti, navernoe, imeet smysl nastroit' ntp na kiske :) [24.10.2000] Basil Dolmatov - 17xx ne podderzhivaet ISL, hardware limitation. I ne budet podderzhivat'. [09.12.2000] Valery Filippov - 4500 ne tyanet 4Mbit na DCE. [27.12.2000] Eugeny Krasilnikov - undocumented Cisco IOS commands http://boerland.com/dotu http://www.cisco.com/univercd/cc/td/doc/product/software/ios121/121newft/121t/121t1/sshv1.htm#10313

    * Cisco-networking-FAQ *

Subject: comp.dcom.sys.cisco Frequently Asked Questions (FAQ) Date: 12 Sep 1997 From: jhawk@panix.com (John Hawkinson) Organization: PANIX Public Access Internet and Unix, NYC Newsgroups: comp.dcom.sys.cisco, comp.protocols.tcp-ip, comp.dcom.servers, comp.answers, news.answers Archive-name: cisco-networking-faq Last-modified: $Date: 1996/04/28 05:55:19 $ Version: $Revision: 1.10 $ This FAQ is edited by John Hawkinson, .

    Administrivia:

Please contribute answers to the questions in the Todo section! If your answer is somewhat complicated, posting would probably be best (to comp.dcom.sys.cisco). Otherwise, e-mail it to cisco-faq@panix.com. Please note that a LOT of these questions have been hanging around for some time, and if knowledgable people could take the time to answer a few of them, that'd help. This draft FAQ is in RFC1153 digest format, so you can follow each question with your newsreader. I suppose that question-numbers should be moved to the From: field. Note that Date: fields represent last-modification times for the questions. Since this FAQ was first developed, cisco has written up a lot of useful information on their web site, http://www.cisco.com. If you can't find what you're looking for here, please check there, too.

    Table of Contents

================= 1. How can I contact cisco? 2. What is this newsgroup? 3. What does ``cisco'' stand for? 4. How do I save the configuration of a cisco? 5. Where can I get ancillary software for my cisco? 6. Is there a World-Wide-Web (www) information source? 7. How can I get my cisco to talk to a third party router over 8. How can I get my cisco to talk to a 3rd-party router over Frame Relay? 9. How can I use debugging? 10. How can I use NTP (Network Time Protocol) with my cisco? 11. Sample cisco NTP Configurations 12. How do I avoid the annoying DNS lookup if I have misspelled a command? 13. Tracing bad routing information 14. How to use access lists 15. The cisco boot process 16. Where can I get cisco hardware? 17. Where can I get IETF documents (RFCs, STDs, etc.)? 18. Future features in cisco software 19. How do cisco routers rate performance-wise? 20. How are packets switched? 21. How does one interpret buffer statistics? 22. How should I restrict access to my router? 23. What can I do about source routing? 24. Is there a block of private IP addresses I can use? 25. Is DHCP supported? 26. Where can I get cisco documentation? 27. What's the latest software for the CSC/3? 28. What IP routing protocol should I use? 29. How do I interpret the output of ``show version''? 30. What is the maximum number of Frame Relay PVCs? 31. How much memory is necessary to telnet to a cisco router? 32. Where can I purchase flash RAM? 33. When are static routes redistributed? 34. When is the next hop of a route considered ``reachable''? 35. How do name and phone number of ``dialer map'' interfere? 36. What's the purpose of the network command? 37. What is VLSM? 38. What are some methods for conserving IP addresses for serial lines? 39. Why do some ip addresses get rejected? 40. How do 4xxx serial numbers correspond to models? 41. Where can I find more info on TACACS+ 99. Acknowledgements.

    todo:

===== * What is SNMP and how can I use it? What software is available and how do I use cisco enterprise MIBs? MIBs on ftpeng.cisco.com and CIO.cisco.com * Pointers to other net resources, like comp.protocols.tcp-ip, RFCs, the firewalls mailing list, etc (bgpd?[or is it cidrd now? :-)]). * Hints about confusing and not-well documented things like xtacacs... * Comments on interoperability issues WRT other vendors. * What's SMARTnet, why should I subscribe, how much does it cost, and what do I get? * What should I name my router, my interfaces, etc.? * Should we adjust the buffer parameters on the routers? What should be the indicator before tunning the buffer parameters? How should one fine tune the buffer parapeters? * What is CIDR and why do I care (or a more general acronym decoder) ? * How do I configure my cisco to use variable-length subnetting ? * Is there a block of private network numbers I can use within my organization only? When should I use them? How do I access them from outside? * What do I do if I have to partition a network number? * Questions and answers about access lists access-list reference list (lots of questions on that) * I forgot to mention that routing DECnet over X.25 is a problem. * Where PD network applications for SLIP/PPP are. * What is HSRP and how does it work? When is it available (10.0) (Hot Standby Routing Protocol) * Should I run 10.0, 10.2, 10.3, 11.1, or what? * What's the difference between IBGP and EBGP? Why should I run BGP? Actual content. =============== ------------------------------

    How can I contact cisco?

From: Question 1 Date: 31 October 1994 Corporate address: cisco Systems 170 West Tasman Drive San Jose, CA 95134 The following phone numbers are available: Technical Assistance Center (TAC) +1 800 553 2447 (553 24HR) +1 800 553 6387 +1 408 526 8209 Customer Service (Documentation, Warranty & +1 800 553 6387 Contract Services, Order Status Engineering +1 800 553 2447 (553 24HR) On-site Services, Time & Materials Service +1 800 829 2447 (829 24HR) Corporate number / general +1 408 526 4000 Corporate FAX (NOT tech support) +1 408 526 4100 The above 800 numbers are US/Canada only. cisco can also be contacted via e-mail: tac@cisco.com Technical Assistance Center tac-euro@cisco.com European TAC cs-rep@cisco.com Literature and administrative (?) requests cs@cisco.com *UNRELIABLE*, special-interest, ``non-support'' Please follow the directions available on CIO before doing this. cisco provides an on-line service for information about their routers and other products, called CIO (cisco Information Online). telnet to cio.cisco.com for more details. The collective experience of this FAQ indicates that it is far wiser to open a case using e-mail than FAXes, which may be mislaid, shredded, etc. For those of you still in the paperfull office (unlike the rest of us), cisco Systems' new corporate address is: 170 West Tasman Drive San Jose, CA 95134 Mail to tac@cisco.com should include your service contract number, your name, telephone number, a brief one line problem/question description, and a case priority in the first 5 lines. For example: Cisco service contract number 92snt1234a First and last name Jane Doe Best number to contact you 415-555-1234 Problem/question description Cannot see Appletalk zones Case Priority 3 CASE PRIORITIES are defined as one of the following: Pri 1 Production network down, critical business impact Pri 2 Production net seriously degraded, serious impact Pri 3 Network degraded, noticeable impact to business Pri 4 General information, non production problems ------------------------------

    What is this newsgroup?

From: Question 2 Date: 26 July 1994 comp.dcom.sys.cisco, which is gatewayed to the mailing list cisco@spot.colorado.edu, is a newsgroup for discussion of cisco hardware, software, and related issues. Remember that you can also consult with cisco technical support. This newsgroup is not an official cisco support channel, and should not be relied upon for answers, particularly answers from cisco Systems employees. Until recently, the mailing list was gatewayed into the newsgroup, one-way. It is possible that this arrangement may resume at somet time in the future. ------------------------------

    What does ``cisco'' stand for?

From: Question 3 Date: 31 October 1994 cisco folklore time: At one point in time, the first letter in cisco Systems was a lowercase ``c''. At present, various factions within the company have adopted a capital ``C'', while fierce traditionalists (as well as some others) continue to use the lowercase variant, as does the cisco Systems logo. This FAQ has chosen to use the lowercase variant throughout. cisco is not C.I.S.C.O. but is short for San Francisco, so the story goes. Back in the early days when the founders Len Bosack and Sandy Lerner and appropriate legal entities were trying to come up with a name they did many searches for non similar names, and always came up with a name which was denied. Eventually someone suggested ``cisco'' and the name wasn't taken (although SYSCO may be confusingly similar sounding). There was an East Coast company which later was using the ``CISCO'' name (I think they sold in the IBM marketplace) they ended up having to not use the CISCO abberviation. Today many people spell cisco with a capital ``C'', citing problems in getting the lowercase ``c'' right in publications, etc. This lead to at least one amusing article headlined ``Cisco grows up''. This winter we will celebrate our 10th year. [This text was written in July of 1994 -jhawk] ------------------------------

    How do I save the configuration of a cisco?

From: Question 4 Date: 31 October 1994 If you have a tftp server available, you can create a file on the server for your router to write to, and then use the write network command. From a typical unix system: mytftpserver$ touch /var/spool/tftpboot/myconfig mytftpserver$ chmod a+w /var/spool/tftpboot/myconfig myrouter#write net Remote host [10.7.0.63]? 10.7.0.2 Name of configuration file to write [myrouter-confg]? myconfig Write file foobar on host 10.7.0.2? [confirm] y Additionally, there's a Macintosh TFTP server available: ftp://nic.switch.ch/software/mac/peterlewis/tftpd-100.sit.hqx Additionally, you can also use expect, available from: ftp://ftp.uu.net/languages/tcl/expect/expect.tar.gz ftp://ftp.cme.nist.gov/expect/expect.tar.gz or, in shar form from ftpeng.cisco.com. Expect allows you to write a script which telnets to the router and performs a ``write terminal'' command, or any other arbitrary set of command(s), using a structured scripting language (Tcl). ------------------------------

    Where can I get ancillary software for my cisco?

From: Question 5 Date: 5 July 1994 Try ftping to ftp://ftpeng.cisco.com/pub It's a hodgepodge collection of useful stuff, some maintained and some not. Some is also available from ftp://cio.cisco.com Vikas Aggarwal has a very customised tacacsd: A new version of xtacacsd is available via anonymous FTP from: ftp://ftp.navya.com/pub/vikas/xtacacsd-3.5.shar.gz ------------------------------

    Is there a World-Wide-Web (www) information source?

From: Question 6 Date: 28 April 1996 You can try the WWW page for this FAQ: http://www.panix.com/cisco-faq/ or the cisco Educational Archive (CEA) home page: http://sunsite.unc.edu/cisco/cisco-home.html or the cisco Information Online (CIO) home page: http://www.cisco.com/ ------------------------------

    How can I get my cisco to talk to a third party router over a serial link?

From: Question 7 Date: 5 July 1994 You need to tell your cisco to use the same link-level protocol as the other router; by default, ciscos use a rather bare variant of HDLC (High-level Data Link Control) all link-level protocols use at some level/layer or another. To make your cisco operate with most other routers, you need to change the encapsulation from HDLC to PPP on the relevant interfaces. For instance: sewer-cgs#conf t Enter configuration commands, one per line. Edit with DELETE, CTRL/W, and CTRL/U; end with CTRL/Z interface serial 1 encapsulation ppp ^Z sewer-cgs#sh int s 1 Serial 1 is administratively down, line protocol is down Hardware is MCI Serial MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, rely 255/255, load 1/255 Encapsulation PPP, loopback not set, keepalive set (10 sec) ^^^^^^^^^^^^^^^^^^^^^^^^^^^ [...] If you're still having trouble, you might wish to turn on serial interface debugging: sewer-cgs#ter mon sewer-cgs#debug serial-interface ------------------------------

    How can I get my cisco to talk to a 3rd-party router over Frame Relay?

From: Question 8 Date: 27 July 1994 You should tell your cisco to use ``encapsulation frame-relay ietf'' (instead of ``encapsulation frame-relay'') on your serial interface that's running frame relay if your frame relay network contains a diverse set of manufacturers' routers. The keyword ``ietf'' specifies that your cisco will use RFC1294-compliant encapsulation, rather than the default, RFC1490-compliant encapsulation (other products, notably Novell MPR 2.11, use a practice sanctioned by 1294 but deemed verbotten by 1490, namely padding of the nlpid). If only a few routers in your frame relay cloud require this, then you can use the default encapsulation on everything and specify the exceptions with the frame-relay map command: frame-relay map ip 10.1.2.3 56 broadcast ietf ^^^^ (ietf stands for Internet Engineering Task Force, the body which evaluates Standards-track RFCs; this keyword is a misnomer as both RFC1294 and RFC1490 are ietf-approved, however 1490 is most recent and is a Draft Standard (DS), whereas 1294 is a Proposed Standard (one step beneath a DS), and is effectively obsolete). ------------------------------

    How can I use debugging?

From: Question 9 Date: 26 July 1994 The ``terminal monitor'' command directs your cisco to send debugging output to the current session. It's necessary to turn this on each time you telnet to your router to view debugging information. After that, you must specify the specific types of debugging you wish to turn on; please note that these stay on or off until changed, or until the router reboots, so remember to turn them off when you're done. Debugging messages are also logged to a host if you have trap logging enabled on your cisco. You can check this like so: sl-panix-1>sh logging Syslog logging: enabled (0 messages dropped, 0 flushes, 0 overruns) Console logging: level debugging, 66 messages logged Monitor logging: level debugging, 0 messages logged Trap logging: level debugging, 69 message lines logged Logging to 198.7.0.2, 69 message lines logged sl-panix-1> If you have syslog going to a host somewhere and you then set about a nice long debug session from a term your box is doing double work and sending every debug message to your syslog server. Additionally, if you turn on something that provides copious debugging output, be careful that you don't overflow your disk (``debug ip-rip'' is notorious for this). One solution to this is to only log severity ``info'' and higher: sl-panix-1#conf t Enter configuration commands, one per line. End with CNTL/Z. logging trap info The other solution is to just be careful and remember to turn off debugging. This is easy enough with: sl-panix-1#undebug all If you have a heavily loaded box, you should be aware that debugging can load your router. The console has a higher priority than a vty so don't debug from the console; instead, disable console logging: cix-west.cix.net#conf t Enter configuration commands, one per line. End with CNTL/Z. no logging console Then always debug from a vty. If the box is busy and you are a little too vigorous with debugging and the box is starting to sink, quickly run, don't walk to your console and kill the session on the vty. If you are on the console your debugging has top prioority and then the only way out is the power switch. This of course makes remote debugging a real sweaty palms adventure especially on a crowded box. Caveat debugger! Also, if you for some reason forget what the available debug commands are and don't have a manual handy, remember that's what on-line help is for. Under pre 9.21 versions, ``debug ?'' lists all commands. Under 9.21 and above, that gives you general categories, and you can check for more specific options by specifying the category: ``debug ip ?''. As a warning, the ``logging buffered'' feature causes all debug streams to be redirected to an in-memory buffer, so be careful using that. Lastly, if you're not sure what debugging criteria you need, you can try ``debug all''. BE CAREFUL! It is way useful, but only in a very controlled environment, where you can turn off absolutely everything you're not interested in. Saves a lot of thinking. Turning it on on a busy box can quickly cause meltdown. ------------------------------

    How can I use NTP (Network Time Protocol) with my cisco?

From: Question 10 Date: 5 July 1994 >What level of software is required for NTP support in >a cisco router? 9.21 or above. >Which cisco routers support NTP? It is a software feature exclusively. Anything that supports 9.21 or 10 will run NTP (when running that s/w). >How do I set it up? The basic hook is: ntp server [version n] or ntp peer [version n] depending on whether you want a client/server or peer relationship. There's a bunch of other stuff available for MD5 authentication, broadcast, access control, etc. You can also use the context-sensitive help feature to puzzle it out; try ``ntp ?'' in config mode. You'll also want to play with the SHOW NTP * router commands. Here are two examples. EXAMPLE 1: router# show ntp assoc address ref clock st when poll reach delay offset disp +~128.9.2.129 .WWVB. 1 109 512 377 97.8 -2.69 26.7 *~132.249.16.1 .GOES. 1 309 512 357 55.4 -1.34 27.5 * master (synced), # master (unsynced), + selected, - candidate, ~ configured EXAMPLE 2: router#show ntp stat Clock is synchronized, stratum 2, reference is 132.249.16.1 nominal freq is 250.0000 Hz, actual freq is 249.9981 Hz, precision is 2**19 reference time is B1A8852D.B69201EE (12:36:13.713 PDT Tue Jun 14 1994) clock offset is -1.34 msec, root delay is 55.40 msec root dispersion is 41.29 msec, peer dispersion is 28.96 msec For particular cisco NTP questions, feel free to ask in comp.dcom.sys.cisco. For broader NTP info, see ftp://louie.udel.edu:pub/ntp/doc. The file clock.txt in that directory has info about various public NTP servers. There is also information on radio time receivers that can be connected to an NTP server (this is handy on private networks, if you have an entire campus to get chiming, or if you become a hard core chimer). The ``ntp clock-period'' command is added automagically to jump-start the NTP frequency compensation when the box is rebooted. This is essentially a representation of the frequency of the crystal used as the local timebase, and may take several days to calculate otherwise. (Do a ``write mem'' after a week or so to save a good value.) Caveat of obsolecence: Note that the CS-500 will not be able to achieve quite the same level of accuracy as other platforms, since its hardware clock resolution is roughly 242Hz instead of the 1MHz available on other platforms. In practice this shouldn't matter for anyone other than true time geeks. ----------------------------------------------------------------------

    Sample cisco NTP Configurations

From: Question 11 Date: 5 July 1994 You will need to substitute your own NTP peers, timezones, and GMT offsets into the examples below, of course. Example 1 is in US Central Time Zone, while example 3 is in US Pacific Time Zone. Both account for normal US Daylight Savings Time practices. EXAMPLE 1 (Charley Kline): ... clock timezone CST -6 clock summer-time CDT recurring ntp source eth 0 ntp peer ntp peer ntp peer ... EXAMPLE 2 (Tony Li): ... ntp source Ethernet0/0 ntp update-calendar ntp peer ntp peer prefer ... EXAMPLE 3 (Dave Katz): ... service timestamps debug datetime localtime service timestamps log datetime localtime clock timezone PST -8 clock summer-time PDT recurring interface Ethernet0 ip address ntp broadcast ntp clock-period 17180319 ntp source Ethernet0 ntp server ntp server ntp server COMMENTS ON EXAMPLE 3: The config file is commented with date and time (and user id, if TACACS is enabled) when the system thinks the clock is accurate. I've enabled timestamping of debug and syslog messages. I send NTP broadcast packets out onto the local ethernet. I'm in Pacific Standard Time, with U.S. standard daylight saving time rules. I use the IP address of the ethernet as the source for all NTP packets. ------------------------------

    How do I avoid the annoying DNS lookup if I have misspelled a command?

From: Question 12 Date: 5 July 1994 By default, all lines are configured to automatically try a telnet connection if the first word in a input line is not recognized as a valid command. You can disable this by setting ``transport preferred none'' on every line (con, aux and vty). For instance: sl-panix-1#conf t Enter configuration commands, one per line. End with CNTL/Z. line vty 0 10 transport preferred none You can see the number of vty's currently configuered with ``show lines'' Also, you can suspend connect attempts with ^^ followed by ``x'', ie shift-cntrl-6 x. [It has been suggested that ``no ip ipname-lookup'' to turn off IEN116 helps. I think this is the default -jhawk ] ------------------------------

    Tracing bad routing information

From: Question 13 Date: 31 Oct 1994 or: How do I find out which non-cisco systems on my networks generate IP-RIP information without letting them mess up my routing tables. Here you could work with a default administrative distance. Administrative distance is the basis upon which the cisco prefers routing information of one protocol over another. In this example: router rip network 192.125.254.0 distance 255 distance 120 192.125.254.17 ! list all valid RIP suppliers [...] the value 255 has the implicit meaning of not putting this information into the routing table. Therefore, setting an administrative distance of 255 means that all RIP suppliers are by default accepted but their information is not put into the routing table. The administrative distance for the router 192.125.244.17 has been reset to the default (for RIP) of 120, causing its routes to be accepted into the routing table. Then you can look them up with ``show ip protocols'' and restore the original administrative distance for the ones you want to fill in the routing table. The same results can be acheived with an ip access-list, but with that, ``show ip protocols'' will only show the valid ones. But often it is more useful to see which systems were generating routing information at all. This trick works for other routing protocols as well, but please select the proper adminstrative distance (rather than 120) for the protocol you're using. ------------------------------

    How to use access lists

From: Question 14 Date: 5 July 1994 [The following is wholesale included; at some point it'll probably be editted a bit and reformatted... -jhawk ] Frequently Asked Questions contributed by Howard C. Berkowitz PSC International hcb@world.std.com @clark.net [probably will be my permanent personal account] PSC's domain is in mid-setup Where in the router are access lists applied? In general, Basic access lists are executed as filters on outgoing interfaces. Newer releases of the cisco code, such as 9.21 and 10, do have increased ability to filter on incoming ports. Certain special cases, such as broadcasts and bridged traffic, can be filtered on incoming interfaces in earlier releases. There are also special cases involving console access. Rules, written as ACCESS-LIST statements, are global for the entire cisco box; they are activated on individual outgoing interfaces by ACCESS-GROUP subcommands of the INTERFACE major command. Filters are applied after traffic has entered on an incoming interface and gone through a routing process; traffic that originates in a router (e.g., telnets from the console port) is not subject to filtering. +-------------------+ | GLOBAL | | | | Routing | | ^ v Access | | ^ v Lists | +-^--v--------^---v-+ | ^ v ^ v | | ^ v ^ v | A----------->|-| |>>>>Access >>----------->B |1 Group 2 | <------------| |<----------- | | | | +-------------------+ Some types of ``filter,'' using ``filter'' as a broader class than ACCESS-LIST, can operate on incoming traffic. For example, the INPUT- SAP-FILTER used for Novell networks is applied to Service Advertisement Packets (SAP) seen at incoming interfaces. In general, incoming filtering can only be done for ``system'' rather than user traffic. Rules of thumb in defining access lists. First, define what you want to do and in which directions. An informal drawing is a good first step. As opposed to the usual connectivity drawings among routers, it's often convenient to draw unidirectional links between routers. Second, informally write out your filtering rules. In general, it is best to go from most specific to least specific. Modify the order of writing things to minimize the number of rules needed. Third, determine which rules need to be on which routers. Explicitly consider the direction of flow, and the possible existence of additional paths that could inadvertently bypass a filter. Can a cisco router be a ``true'' firewall? This depends on the definition of firewall. Some writers (e.g., Gene Spafford in _Practical UNIX Security_) define a firewall as a host on which an ``inside'' and/or an ``outside'' application process run, with application-level code linking the two. For example, a firewall might provide FTP access to the outside world, but it would not also provide direct FTP service to the inside world. To place a file on the FTP external server, a designated user would explicitly log onto the FTP server, transfer a file to the server, and log off. The firewall prevents direct FTP connectivity between the inside and outside networks; only indirect, application-level connectivity is allowed. Firewalls of this sort are complemented by chokes, which filter on network addresses and/or port numbers. Cisco routers cannot do application-level control with access control lists. Other authors do not distinguish between chokes and filters. Using the loose definition that a firewall is anything that selectively blocks access from the inside to the outside, routers can be firewalls. IP Specific ----------- Can the ``operand'' field be used with a protocol keyword of IP to filter on protocol ID? No. Operand filtering only works for TCP and UDP port numbers. How can I prevent traffic for a certain Internet application to flow in one direction but not the other? Remember that Internet applications flow from client port to server port. Denying traffic from port 23, for example, blocks flow from the client to the server. +-------------------+ | | A----------->| |----------->B |1 2| <------------| |<----------- | | +-------------------+ If we deny traffic to Port 23 of address B by placing a filter at interface 2, we have blocked A's ability to telnet to B, but not B's ability to telnet to A. A second filter at interface A would be needed to block telnet in both directions. Assume that we only have the filter at interface 2. Telnets to A from B will not be affected because the filter at 2 does not check incoming traffic. ------- With the arrival of in-bound access lists in 9.21, it should be noted that both inbound and access lists are about equally efficient, in case any of you were wondering. It's worth remembering that there are some kinds of problems that packet-filtering firewalls are not best suited for. There's reasonably good information in: "Network (in)security through packet filtering" ftp://ftp.greatcircle.com/pub/firewalls/pkt_filtering.ps.Z ------------------------------

    The cisco boot process

From: Question 15 Date: 26 July 1994 What really happens when a cisco router boots, from boot start to live interfaces? First it boots the ROM os version. It reads the config. Now, it realizes that you want to netboot. It loads the netbooted copy in on top of itself. It then re-initializes the box and re-reads the config. Manly, yes, but we like it too.... [[ Ummm... in particular it loads the netbooted copy in as WELL as itself, decompresses it, if necessary, and THEN loads on top of itself. Note that this is important because it tells you what the memory requirements are for netbooting: RAM for ROM image (if it's a run from RAM image), plus dynamic data structures, plus RAM for netbooted image. ]] The four ways to boot and what happens (sort of): I (from bootstrap mode) The ROM monitor is running. The I command causes the ROM monitor to walk all of the hardware in the bus and reset it with a brute force hammer. If the bits in the config register say to auto-boot, then goto B B (from bootstrap mode) Load the OS from ROM. If a name is given, tell that image to start silently and then load a new image. If the boot system command is given, then start silently and load a new image. powercycle Does some delay stuff to let the power settle. Goto I. reload (from the EXEC) Goto I. ------------------------------

    Where can I get cisco hardware?

From: Question 16 Date: 18 July 1994 Try calling 800-553-NETS and asking for your local sales office. That's probably the best plan. ------------------------------

    Where can I get IETF documents (RFCs, STDs, etc.)?

From: Question 17 Date: 18 April 1995 Where and how to get new RFCs ============================= RFCs may be obtained via EMAIL or FTP from many RFC Repositories. The Primary Repositories will have the RFC available when it is first announced, as will many Secondary Repositories. Some Secondary Repositories may take a few days to make available the most recent RFCs. Primary Repositories: RFCs can be obtained via FTP from DS.INTERNIC.NET, NIS.NSF.NET, NISC.JVNC.NET, FTP.ISI.EDU, WUARCHIVE.WUSTL.EDU, SRC.DOC.IC.AC.UK, FTP.CONCERT.NET, or FTP.SESQUI.NET. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Secondary Repositories: Sweden ------ Host: sunic.sunet.se Directory: rfc Host: chalmers.se Directory: rfc Germany ------- Site: EUnet Germany Host: ftp.Germany.EU.net Directory: pub/documents/rfc France ------ Site: Institut National de la Recherche en Informatique et Automatique (INRIA) Address: info-server@inria.fr Notes: RFCs are available via email to the above address. Info Server manager is Mireille Yamajako (yamajako@inria.fr). Netherlands ----------- Site: EUnet Host: mcsun.eu.net Directory: rfc Notes: RFCs in compressed format. France ------ Site: Centre d'Informatique Scientifique et Medicale (CISM) Contact: ftpmaint@univ-lyon1.fr Host: ftp.univ-lyon1.fr Directories: pub/rfc/* Classified by hundreds pub/mirrors/rfc Mirror of Internic Notes: Files compressed with gzip. Online decompression done by the FTP server. Finland ------- Site: FUNET Host: funet.fi Directory: rfc Notes: RFCs in compressed format. Also provides email access by sending mail to archive-server@funet.fi. Norway ------ Host: ugle.unit.no Directory: pub/rfc Denmark ------- Site: University of Copenhagen Host: ftp.denet.dk Directory: rfc Australia and Pacific Rim ------------------------- Site: munnari Contact: Robert Elz Host: munnari.oz.au Directory: rfc rfc's in compressed format rfcNNNN.Z postscript rfc's rfcNNNN.ps.Z United States ------------- Site: cerfnet Contact: help@cerf.net Host: nic.cerf.net Directory: netinfo/rfc Site: NASA NAIC Contact: rfc-updates@naic.nasa.gov Host: naic.nasa.gov Directory: files/rfc Site: NIC.DDN.MIL (DOD users only) Contact: NIC@nic.ddn.mil Host: NIC.DDN.MIL Directory: rfc/rfcnnnn.txt Note: DOD users only may obtain RFC's via FTP from NIC.DDN.MIL. Internet users should NOT use this source due to inadequate connectivity. Site: uunet Contact: James Revell Host: ftp.uu.net Directory: inet/rfc UUNET Archive ------------- UUNET archive, which includes the RFC's, various IETF documents, and other information regarding the internet, is available to the public via anonymous ftp (to ftp.uu.net) and anonymous uucp, and will be available via an anonymous kermit server soon. Get the file /archive/inet/ls-lR.Z for a listing of these documents. Any site in the US running UUCP may call +1 900 GOT SRCS and use the login "uucp". There is no password. The phone company will bill you at $0.50 per minute for the call. The 900 number only works from within the US. ------------------------------

    Future features in cisco software

From: Question 18 Date: 22 April 1996 [This could be more fleshed out (still!)] Kerberos and RADIUS in 11.1 RIP version 2 in 11.1 (allows VSM, etc.) Policy-based routing (routing based on source address or interface, or just about anything else you want) in 11.0 *released* PPP Multilink in 11.0(3) *released* Frame Relay payload compression in 11.0(4) *released* IPX Per-Host load balancing in 11.1 ------------------------------

    How do cisco routers rate performance-wise?

From: Question 19 Date: 27 July 1994 People often ask about performance of the cisco routers and are shyed away from answering their questions because we don't know where to send them. Scott Bradner keeps the results of his performance tests on the Internet. You can find them for ftp on the system hsdndev.harvard.edu in the /pub/ndtl. There is a README file in that directory that explains what is available. In addition, cisco has just started publishing a piece of literature called ``The Harvard Benchmark Test Results: Summary of cisco Systems Performance''. The only number I can find on the doc is Lit. #700901. Don't know if you can order it by this number, but at least there's a title to go on. ------------------------------

    How are packets switched?

From: Question 20 Date: 22 April 1996 There are 3 basic types of switching (in order of increasing performance). process switching fast switching autonomous switching Process and fast switching support inbound and outbound, simple and extended, access lists. Of course, for fast switching, such lists only restrict traffic on the particular fast-switched interface. Autonomous switching is done in the switch processor, a microcoded device that is capable of switching IP, IPX, and bridging packets in the 100kpps range. This is known as the "SP" card on the 7000 and the CBUS controller on the AGS+. Encapsulation support is rather limited (Ethernet, HDLC, HSSI...). The cisco 7000 also supports: silicon switching Silicon switching is done in the silicon switching engine (creative, eh? ;-). The silicon switch processor (SSP) is the board which combines both the switch processor and a silicon switching engine. The SSP supports simple and extended outbound access lists in 10.3 and later. The SSP supports simple and extended inbound access lists in 11.1 and later. The cisco 75xx series supports: "optimal" switching (cruddy name, eh?) "flow" switching "distributed" switching * "optimal" switching (cruddy name, eh?) The 7500 platform does not have a separate SP or SSP card, rather the RISC processor on the "integrated route/switch processor card (IRSP)" handles switching directly, similar to the 4000 series routers. There are several hardware and software enhancements made though to increase the throughput to a level that is several times above what you would normally get from "fast" switching. Everything that "fast" switching supports is supported in "optimal" switching. * "flow" switching Basicly the "optimal" switching method, however things have been front-ended with an additional small "flow" cache. This flow cache contains information about source/destination addresses & ports which allow the router to make more informed queueing decisions and process access lists faster. This is a win in routers that would tend to carry a reasonably small number of flows at any one time, such as what you would expect in a corporate network or in a smaller internet service provider network. It's unclear if there are any advantages in a large internet backbone. * "distributed" switching cisco has announced a new type of interface-processor card, called a "VIP" available in the 7500 platform that is intelligent enough to switch packets with no intervention on the part of the IRSP card. This once again separates switching from routing, as in the earlier CBUS/SP/SSP design. The first packet of every session or connection is always Process Switched. The route table is consulted (this resides in DRAM on the CPU) and the "result" is cached in the system memory cache. If the protocol can only be process switched, then it will continue this way and interrupt the CPU for a route table lookup each time. [comment: Process Switching is brutally slow compared to other switching methods. Some features (usually new features do this for the first few software releases) force every packet to be process switched. If you can't avoid process-switching every packet, at least get a router with a fast CPU, such as the 75xx, 4500, and 4700. The 4700 is currently the fastest at process-switching packets, with the 4500 and 75xx tied for second. The 75xx can optimum-switch, however, so it's a lot faster than either of the 4x00s, if you can use it). The second and subsequent packets of each session are capable of being Fast Switched (more session types are becoming fast-switchable), and will consult only the route-cache. This still involves a memory lookup on the board, but the packet can be transferred from the source card directly to the destination card without requiring full storage on the CSC [the CSC refers to the CPU card, basically]. There are some undocumented commands that are useful for obtaining per-interface statistics on what sort of switching was performed. For instance: frobozz-magic-robot>sh int atm4/0 switch ATM4/0 Throttle count: 0 Protocol Path Pkts In Chars In Pkts Out Chars Out IP Process 104851 7669968 116378 11180988 Cache misses 35826 Fast 0 0 0 0 Auton/SSE 0 0 0 0 frobozz-magic-robot>sh int atm4/0 stat ATM4/0 Switching path Pkts In Chars In Pkts Out Chars Out Processor 105024 7679155 116422 11184108 Route cache/FIB 0 0 0 0 Distributed cache 0 0 0 0 Total 105024 7679155 116422 11184108 ------------------------------

    How does one interpret buffer statistics?

From: Question 21 Date: 31 October 1994 Buffer statistics may be obtained with: mit2-gw.near.net>sh buffers Buffer elements: 433 in free list (500 max allowed) 82320311 hits, 0 misses, 0 created Small buffers, 104 bytes (total 202, permanent 120): 185 in free list (20 min, 250 max allowed) 34289219 hits, 4297 misses, 1307 trims, 1389 created Middle buffers, 600 bytes (total 104, permanent 90): 102 in free list (10 min, 200 max allowed) 6829533 hits, 1432 misses, 483 trims, 497 created Big buffers, 1524 bytes (total 90, permanent 90): 90 in free list (5 min, 300 max allowed) 3403884 hits, 56 misses, 1 trims, 1 created Large buffers, 5024 bytes (total 5, permanent 5): 5 in free list (0 min, 30 max allowed) 49984 hits, 13 misses, 20 trims, 20 created Huge buffers, 18024 bytes (total 0, permanent 0): 0 in free list (0 min, 4 max allowed) 0 hits, 0 misses, 0 trims, 0 created 5683 failures (0 no memory) You can interpret them: Total Number of buffers of that size that exist. Free Number of free buffers. Max Maximum size that the free list can grow to before we start throwing them away. Hit Buffer got used. Miss Someone requested a buffer and we had to go carve it up out of free memory. If we couldn't because we were at interrupt level, it's also an allocation failure. If we couldn't because we were out of memory, then it's also a ``no memory'' failure. Trim There are more free buffers on the free list than there need to be and we threw some away. Create Number of buffers we created after a miss. ------------------------------

    How should I restrict access to my router?

From: Question 22 Date: 22 April 1996 Many admins are concerned about unauthorized access to their routers from malicious people on the Internet; one way to prevent this is to restrict access to your router on the basis of IP address. Many people do this, however it should be noted that a significant number of network service providers allow unrestricted access to their routers to allow others to debug, examine routes, etc. If you're comfortable doing this, so much the better, and we thank you! If you wish to restrict access to your router, select a free IP access list (numbered from 1-100) -- enter ``sh access-list'' to see those numbers in use. yourrouter#sh access-list Standard IP access list 5 permit 192.94.207.0, wildcard bits 0.0.0.255 Next, enter the IP addresses you wish to allow access to your router from; remember that access lists contain an implicit "deny everything" at the end, so there is no need to include that. In this case, 30 is free: yourrouter#conf t Enter configuration commands, one per line. End with CNTL/Z. yourrouter(config)#access-list 30 permit 172.30.0.0 0.0.255.255 yourrouter(config)#^Z (This permits all IP addreses in the network 172.30.0.0, i.e. 172.30.*.*). Enter multiple lines for multiple addresses; be sure that you don't restrict the address you may be telnetting to the router from. Next, examine the output of ``sh line'' for all the vty's (Virtual ttys) that you wish to apply the access list to. In this example, I want lines 2 through 12: yourrouter#sh line Tty Typ Tx/Rx A Modem Roty AccO AccI Uses Noise Overruns 0 CTY - - - - - 0 0 0/0 1 AUX 9600/9600 - - - - - 1 3287605 1/0 * 2 VTY 9600/9600 - - - - 7 55 0 0/0 3 VTY 9600/9600 - - - - 7 4 0 0/0 4 VTY 9600/9600 - - - - 7 0 0 0/0 5 VTY 9600/9600 - - - - 7 0 0 0/0 6 VTY 9600/9600 - - - - 7 0 0 0/0 7 VTY 9600/9600 - - - - 7 0 0 0/0 8 VTY 9600/9600 - - - - 7 0 0 0/0 9 VTY 9600/9600 - - - - 7 0 0 0/0 10 VTY 9600/9600 - - - - 7 0 0 0/0 11 VTY 9600/9600 - - - - - 0 0 0/0 12 VTY 9600/9600 - - - - - 0 0 0/0 Apply the access list to the relevant lines: yourrouter#conf t Enter configuration commands, one per line. End with CNTL/Z. yourrouter(config)#line 2 12 yourrouter(config-line)# access-class 30 in yourrouter(config-line)# ^Z (This apply access list 30 to lines 2 through 12. It's important to restrict access to the aux port (line 1) if you have a device (such as a CSU/DSU) plugged into it.a) Be sure to save your configuration with ``write mem''. Please note that access lists for incoming telnet connections do NOT cause your router to perform significant CPU work, unlike access lists on interfaces. ------------------------------

    What can I do about source routing?

From: Question 23 Date: 1 November 1994 What *is* source routing? Soure routing is an IP option which allows the originator of a packet to specify what path that packet will take, and what path return packets sent back to the originator will take. Source routing is useful when the default route that a connection will take fails or is suboptimal for some reason, or for network diagnostic purposes. For more information on source routing, see RFC791. Unfortunately, source routing is often abused by malicious users on the Internet (and elsewhere), and used to make a machine (A), think it is talking to a different machine (B), when it is really talking to a third machine (C). This means that C has control over B's ip address for some purposes. The proper way to fix this is to configure machine A to ignore source-routed packets where appropriate. This can be done for most unix variants by installing a package such as Wietse Venema, ,'s tcp_wrapper: ftp://cert.org:pub/tools/tcp_wrappers For some operating systems, a kernel patch is required to make this work correctly (notably SunOS 4.1.3). Also, there is an unofficial kernel patch available for SunOS 4.1.3 which turns all source routing off; I'm not sure where this is available, but I believe it was posted to the firewalls list by Brad Powell soimetime in mid-1994. If disabling source routing on all your clients is not posssible, a last resort is to disable it at your router. This will make you unable to use ``traceroute -g'' or ``telnet @hostname1:hostname2'', both of which use LSRR (Loose Source Record Route, 2 IP options, the first of which is a type of source routing), but may be necessary for some. If so, you can do this with foo-e-0#conf t Enter configuration commands, one per line. End with CNTL/Z. foo-e-0(config)#no ip source-route foo-e-0(config)#^Z It is somewhat unfortunate that you cannot be selective about this; it disables all forwarding of source-routed packets through the router, for all interfaces, as well as source-routed packets to the router (the last is unfortunate for the purposes of ``traceroute -g''). ------------------------------

    Is there a block of private IP addresses I can use?

From: Question 24 Date: 22 April 1996 Yes there is, however whether you wish to do so is an issue of some debate. You could consult: 1627 Network 10 Considered Harmful (Some Practices Shouldn't be Codified). E. Lear, E. Fair, D. Crocker & T. Kessler. June 1994. (Format: TXT=18823 bytes) 1918 Address Allocation for Private Internets. Y. Rekhter, B. Moskowitz, D. Karrenberg, G. J. de Groot & E. Lear. February 1996. (Format: TXT=22270 bytes) (Obsoletes RFC1627, RFC1597) (Also BCP0005) In any event, RFC 1918 documents the allocation of the following addresses for use by ``private internets'': 10.0.0.0 - 10.255.255.255 172.16.0.0 - 172.31.255.255 192.168.0.0 - 192.168.255.255 Most importantly, it is vital that nothing using these addresses should ever connect to the global Internet, or have plans to do so. Please read the above RFCs before considering implementing such a policy. As an additional note, some Internet providers provide network-management services, statistics gathering, etc. It is unlikely (if at all possible) that they would be willing to perform those services if you choose to utilize private address space. With the increasing popularity and reliability of address translation gateways, this practice is becoming more widely accepted. Cisco has acquired Network Translation, who manufacture such a product. It is now available as the Cisco Private Internet Exchange. With it, you can use any addressing you want on your private internet, and the gateway will insure that the invalid addresses are converted before making out onto the global Internet. It also makes a good firewall. Information on this product is available at http://www.cisco.com/warp/public/751/pix/index.html ------------------------------

    Is DHCP supported?

From: Question 25 Date: 18 April 1995 DHCP, the Dynamic Host Configuration Protocol (RFC1533), is essentially a more extended and flexible version of BOOTP, which allows configuration parameters and other control information to be carried to hosts. Forwarding of DHCP packets (to a DHCP server elsewhere in the network) is supported in 9.21(4) and 10.0(3), as well as later releases. ------------------------------

    Where can I get cisco documentation?

From: Question 26 Date: 18 April 1995 Cisco no longer distributes printed documentation with their routers; instead, they distribute a CDROM. Paper documentation may be purchased, however if you purchase a support contract, documentation is free. Cisco documentation is also available on the web -- if you have a fast Internet conneciton this may be more useful than the CD. Try: http://www.cisco.com/univercd/data/doc/product.htm ------------------------------

    What's the latest software for the CSC/3?

From: Question 27 Date: 18 April 1995 The last supported release on the CSC/3 is 9.1(15). cisco does not plan to release further software for the CSC/3. ------------------------------

    What IP routing protocol should I use?

From: Question 28 Date: 19 May 1995 This is a really complicated question, and a full answer is beyond the scope of this document. Here are the beginnings of an answer. Note that Hello is no longer shipped with cisco routers, and that EGP has been declared Historical (and thus obsolete) by the IETF. Don't use them. Protocol RIP HELLO IGRP OSPF EIGRP IS-IS EGP BGP4 -------------------------------------------------------------------------- Type IGP IGP IGP IGP IGP IGP EGP EGP Algorithm DV DV DV SPF DUAL SPF DV PV Metrics Hopcnt Delay Speed Arb. Speed Arb. Policy Policy Convergence Slow Unstb Mdt Fast Fast Fast Slow Fast Standard? IETF No No IETF No ISO Hist. IETF Complexity Simple Simple Simple Complx Complx Complx Simple Complx Multipath? Yes Yes Yes Yes Yes Yes Yes [*] Var-netmask? No No No Yes Yes Yes No YES Notes ----- IGP = interior gateway protocol, used to build routing tables within an AS. EGP = exterior gateway protocol, used to communicate reachability information between AS's. Algorithms ---------- DUAL = DV with diffusing update algorithm (Garcia-Luna-Aceves et al) DV = Distance Vector (Bellman-Ford) PV = "Path Vector" SPF = Shortest-path-first (Dijkstra) Metrics ------- A metric is how the protocol measures the network to determine the "best" path. "Speed" refers typically to link speed, not available bandwidth. "Arb." indicates that the metrics are arbitrary and configurable. HELLO tried to use available bandwidth by monitoring round-trip delay, but was not generally successful at this. Metrics are not directly exchangable when redistributing routing information from one protocol to another. IGRP and EIGRP use compatible and automatically convertable metrics. Convergence ----------- Qualitatively, convergence measures how fast routers using this protocol will adapt to changes in the topology of the network. "Unstb" indicates a protocol which in general never decided on a stable configuration but continually oscillated between alternatives. Complexity ---------- An observation of how complex the protocol is to implement. Multipath --------- Multipath indicates whether the protocol support and transport multiple equal- or different- cost pathways across between endpoints? [*] indicates that BGP4 supports multipath for IBGP (Internal BGP, a full mesh of all border routers within an AS), but not for EBGP (External BGP). Variable netmask (Var-netmask) ------------------------------ Indicates whether the protocol allows for and transports different masks for the subnets of a routed network. ------------------------------

    How do I interpret the output of ``show version''?

From: Question 29 Date: 18 April 1995 Typing ``show version'' or ``show hardware'' yields a response like: prospect-gw.near.net>sh version Cisco Internetwork Operating System Software IOS (tm) GS Software (GS7), Experimental Version 10.2(11829) [pst 113] System-type (imagename) Version major.minor(release.interim)[who] Desc System-type: type of system the software is designed to run on. imagename: The name of the image. This is different (slightly) for run-from-rom, run-from-flash, and run-from-ram images, and also for subset images which both were and will be more common. "Version": text changes slightly. For example, if an engineer gives you a special version of software to try out a bug fix, this will say experimental version. Major: Major version number. Changes (in theory) when there have been major feature additions and changes to the softare. Minor: minor version number. Smaller but still signficant feature added. (in reality, cisco is not very sure what the difference between "major" and "minor" is, and sometimes politics gets in the way, but either of these "incrementing" indicates feature additions.) EXCEPT: 9.14, 9.17, and 9.1 are all somewhat similar. 9.1 is the base, 9.14 adds specical feature for low end systems, 9.17 added special features specific the high end (cisco-7000) This was an experiment that we are trying not to repeat. release: increments (1 2 3 4 ...) for each maintenance release of released software. Increments for every compile in some other places. interim: increments on every build of the "release tree", which happens weekly for each release, but is only made into a generically shipping maintenance release every 7 to 8 weeks or so. [who]: who built it. Has "fc 1" or similar for released software. has something like [billw 101] for test software built Bill Westfield (billw@cisco.com). Desc: additional description. The idea is that the image name and version number UNIQUELY identify a set of sources and debugging information somewhere back at cisco, should anything go wrong. Copyright (c) 1986-1995 by cisco Systems, Inc. Compiled Thu 09-Mar-95 23:54 by tli Image text-base: 0x00001000, data-base: 0x00463EB0 Copyright, compilation date (and by whom), as well as the starting address of the image. ROM: System Bootstrap, Version 5.0(7), RELEASE SOFTWARE ROM: GS Software (GS7), Version 10.0(7), RELEASE SOFTWARE (fc1) The version of ROM bootstrap software, and the version of IOS in ROM. prospect-gw.near.net uptime is 2 weeks, 4 days, 18 hours, 38 minutes System restarted by reload How long the router has been up, and why it restarted. System image file is "sse-current", booted via flash How the router was booted. RP (68040) processor with 16384K bytes of memory. Type of processor. G.703/E1 software, Version 1.0. X.25 software, Version 2.0, NET2, BFE and GOSIP compliant. Bridging software. ISDN software, Version 1.0. Various software options compiled in. 1 Silicon Switch Processor. 2 EIP controllers (8 Ethernet). 2 FSIP controllers (16 Serial). 1 MIP controller (1 T1). 8 Ethernet/IEEE 802.3 interfaces. 16 Serial network interfaces. 128K bytes of non-volatile configuration memory. 4096K bytes of flash memory sized on embedded flash. Hardware configuration. Configuration register is 0x102 Lastly, the "configuration register", which may be set via software in current releases... ------------------------------

    What is the maximum number of Frame Relay PVCs?

From: Question 30 Date: 22 April 1996 This is covered fairly thoroughly in Product Info/Product Bulletin/Frame Relay Broadcast Queue, Cisco Product Bulletin # 256, available on CIO. Via the web (requires CIO username and pasword) http://cio.cisco.com/warp/customer/417/38.html An excerpt: (Virtual Interfaces) It should be noted that in the IOS (Internetworking Operating System) 10.0 software there is a limit of 256 Virtual and physical interfaces. Hence, if each DLCI is given its own virtual interface, the router is limited to 256 DLCIs. This restriction is expected to be removed in a future release. In most scenarios, it is not necessary that each DLCI have its own Virtual Interface. In particular, IP has the facility which allows disabling of split-horizon routing and hence does not require Virtual Interfaces to support partial mesh topologies. (Appendix 1: How many DLCIs Can Cisco Support on an Interface?) This question is similar to the question of how many PCs can you put on an Ethernet. In general, you can put a lot more than you should given performance and availability constraints. When dimensioning a router in a large network, the following issues should be considered: DLCI Address Space: The only hard limits are the roughly 1000 DLCI limit due to the 10 bit DLCI address space in the Frame Relay frame header. LMI Status Update: The LMI protocol requires that all status reports fit into a single packet and generally limits the number of DLCIs to less than 800. Max DLCIs (approx) = (MTU -20)/5, where MTU is the MTU size in bytes on the Frame Relay link. Broadcast Replication: When sending, the router must replicate the packet on each DLCI and this causes congestion on the access link. The Broadcast Queue reduces this problem. In general, the network should designed to keep the routing update load to below 20 percent of the access lines speed. It is also important that memory requirements for the Broadcast Queue be considered. A good technique to reduce this restriction is the use of default route or extending the update timers. Broadcast Receipt: When receiving, the router must receive updates from the network. The issue here is that the upstream switch can be overloaded and drop packets. When routing updates are dropped, routing instability occurs. Again, the receiving routing update load should be kept to less than 20 percent of the access link speed and preferably lower. Where very high speed links are used, a limit of 128 Kbit/s worth of routing updates is recommended. Routing Stability: When using a link state protocol to reduce the update traffic, the dimensioning should be done assuming the periodic update process and the worst case for Link State Updates (i.e., assuming link and power instability). Dimensioning should not be based on the Hello traffic. As a rule of thumb, dimension assuming a distance vector protocol, but assume that extra bandwidth is available for user data. User Data Traffic: Clearly, the number of DLCIs is dependent on the traffic on each DLCI and the performance requirements to be met. In general, Frame Relay accesses should be run at lower loads than router-to-router links since the prioritisation capabilities are not as strong in many cases and in general the marginal costs of increasing access link speed are lower than with dedicated lines. Many of the issues covered here are included in the Internet Design Guide manual that Cisco provides. Update: The limit of 256 PVCs goes away in IOS 11.1. I think the number is now something like 1024 per router or some even more ludicrous number. There are still lots of reasons you never want to do that. ;-) The limit of 256 PVCs goes away in IOS 11.1. I think the number is now something like 1024 per router or some even more ludicrous number. There are still lots of reasons you never want to do that. ;-) ------------------------------

    How much memory is necessary to telnet to a cisco router?

From: Question 31 Date: 18 April 1995 In order to login to a cisco router, it needs to have at least 64k of contiguous free memory. ------------------------------

    Where can I purchase flash RAM?

From: Question 32 Date: 18 April 1995 There are two varieties: MEM-1X8F 8meg MEM-2X8F 16meg ******************************************************************************* ******************************* 2500 ******************************** ******************************* 8M Flash ******************************** ******************************************************************************* PRODUCT# QTY -------- --- MEM-1X8F 1 MEM-2X8F 2 Part Number: 16-0975-01 Description: IC,FEPROM, 2Mx32,100ns,SIM80 SC: P REV: A0 S/UM: EA P/UM: EA ------------------------------------------------------------------------------- VENDOR ITM MANUFACTURER'S PART CODE MANUFACTURER'S NAME --- -------------------- ---------- ------------------------------ 1- 1 SM732C2000B-10 KITTING01 SMART MODULE Smart Modular is located in Freemont, California. For small orders, Smart Modular recommends you contact: PC Complete 800-849-4622. They carry both Flash RAM and DRAM. ------------------------------

    When are static routes redistributed?

From: Question 32 Date: 19 May 1995 In the simple case, any static route *in the routing table* is redistributed if the ``redistribute static'' command is used, and some filter (set with either ``route-map'' or ``distribute-list out'') doesn't filter it out. Whether the static route gets into routing table depends on: Whether the next hop address is reachable (if you use static route pointing to a next hop) OR Whether the interface is up (if you use static route pointing to an interface). If one of these is true, an attempt is made to add the route to the routing table; whether that succeeds depends on the administrative distance of the route -- a lower administrative distance (the route is "closer") than a preexisting route will cause the preexisting route to be overwritten. ------------------------------

    When is the next hop of a route considered ``reachable''?

From: Question 33 Date: 19 May 1995 When a static route is added, or during an important event (eg: interface up/down transition), the next hop for a route is looked up from the routing table (i.e. recursive routing). As a consequence, if a route which is depended upon for evaluation of the next hop of a static route goes away, a mechanism is required to remove that (now-invalid) static route. Scanning all static routes each time the routing table changes is too expensive, so instead, a period timer is used. One a minute, static routes are added and removed from the routing table based on the routes they depend upon. It should be noted that a particular static route will be reevaluated when its interface transitions up or down. ------------------------------

    How do name and phone number of ``dialer map'' interfere?

From: Question 35 Date: 22 April 1996 How do name and phone number of `dialer map' interfere? We use the telephone number first actually. If the caller id matches the telephone number to call, then you don't need the 'name' parameter with a phone number. I realized that the above is ambiguous, so let's do this. You have: dialer map ip x.x.x.x name is used for incoming authentication. It can be either the hostname, for PAP and CHAP, or it can be a number as returned by caller id. If this is not there, and it is an imcoming call, and there is caller id, we will compare against to see if that matches. Not sure I've been clear here. ------------------------------

    What's the purpose of the network command?

From: Question 36 Date: 22 April 1996 >* what is the real purpose of the network subcommand of > router commands? When do I not want to include a network > I know about? The real purpose of the 'network' sub-command of the router commands is to indicate what networks that this router is connected to are to be advertised in the indicated routing protocol or protocol domain. For example, if OSPF and EIGRP are configured, some subnets may be advertised in one and some in the other. The network command enables one to do this. An example of such a case is a secure subnet. Imagine the case where a set of subnets are permitted to communicate within a campus, but one of the buildings is intended to be inaccessible from the outside. By placing the secure subnet in its own network number and not advertising the number, the subnet is enabled to communicate with other subnets on the same router, but is unreachable from any other router, barring static routes. This can be extended by using a different routing protocol or routing protocol domain for the secure network; subnets on the various routers within the secure domain are mutually reachable, and routes from the non-secure domain may be leaked into the secure domain, but the secure domain is invisible to the outside world. ------------------------------

    What is VLSM?

From: Question 37 Date: 22 April 1996 A Variable Length Subnet Mask (VLSM) is a means of allocating IP addressing resources to subnets according to their individual need rather than some general network-wide rule. Of the IP routing protocols supported by Cisco, OSPF, Dual IS-IS, BGP-4, and EIGRP support "classless" or VLSM routes. Historically, EGP depended on the IP address class definitions, and actually exchanged network numbers (8, 16, or 24 bit fields) rather than IP addresses (32 bit numbers); RIP and IGRP exchanged network and subnet numbers in 32 bit fields, the distinction between network number, subnet number, and host number being a matter of convention and not exchanged in the routing protocols. More recent protocols (see VLSM) carry either a prefix length (number of contiguous bits in the address) or subnet mask with each address, indicating what portion of the 32 bit field is the address being routed on. A simple example of a network using variable length subnet masks is found in Cisco engineering. There are several switches in the engineering buildings, configured with FDDI and Ethernet interfaces and numbered in order to support 62 hosts on each switched subnet; in actuality, perhaps 15-30 hosts (printers, workstations, disk servers) are physically attached to each. However, many engineers also have ISDN or Frame Relay links to home, and a small subnet there. These home offices typically have a router or two and an X terminal or workstation; they may have a PC or Macintosh as well. As such, they are usually configured to support 6 hosts, and a few are configured for 14. The point to point links are generally unnumbered. Using "one size fits all" addressing schemes, such as are found in RIP or IGRP, the home offices would have to be configured to support 62 hosts each; using numbers on the point to point links would further compound the address bloat. One configures the router for Variable Length Subnet Masking by configuring the router to use a protocol (such as OSPF or EIGRP) that supports this, and configuring the subnet masks of the various interfaces in the 'ip address' interface sub-command. To use supernets, one must further configure the use of 'ip classless' routes. ------------------------------

    What are some methods for conserving IP addresses for serial lines?

From: Question 38 Date: 22 April 1996 VLSM and unnumbered point to point interfaces are the obvious ways. The 'ip unnumbered' subcommand indicates another interface or sub-interface whose address is used as the IP source address on messages that the router originates on the unnumbered interface, such as telnet or routing messages. By doing this, the router is reachable for management purposes (via the address of the one numbered interface) but consumes no IP addresses at all for its unnumbered links. When a serial ip interface connects several sites, as an SMDS link might, then the use of an appropriate subnet mask (and a routing protocol that can make good use of the information) will minimize address consumption. ------------------------------

    Why do some ip addresses get rejected?

From: Question 39 Date: 23 April 1996 How come my cisco router doesn't accept an address like: "ip address 192.111.107.1 255.255.255.240" or "ip address 171.69.0.1 255.255.0.0" When "subnetting" of IP networks was first sanctioned by the IETF, the first and last subnets (the all zeros subnet and all ones subnet) were reserved for rather obscure uses and because of the confusion that would be caused with routing protocols that don't carry net mask information. It was technically illegal to place hosts or routers on those two subnets. Several hosts and most other vendor's router products have problems operating with the reserved subnets, so their use is discouraged. However, in 1995, the IETF removed the restrictions on the use of these reserved subnets as part of the classless routing effort. If you would like to use the reserved subnets, simply add the line "ip subnet-zero" to your cisco configuration. You might consider adding "ip subnet-zero" to all your configurations as a metter of course, to avoid being bitten by this in the future. ------------------------------

    How do 4xxx serial numbers correspond to models?

From: Question 40 Date: 27 April 1996 show version serial # Label ------------------------------------------------------- 4000 Rev A0 440xxxxx C4000 4000M Rev B0 445xxxxx C4000 4500 450xxxxx C4500 4500M 455xxxxx C4500 4700 470xxxxx C4700 ------------------------------

    Where can I find more info on TACACS+

From: Question 41 Date: 28 April 1996 In addition to sundry cisco documentation and ftp-able info, there exists a TACACS+ mailing list. For more information, see http://www.disaster.com/tacplus/. ------------------------------

    Acknowledgements.

From: Question 99 Date: 19 May 1995 The following people contributed to this FAQ, and their contributions are greatly appreciated, both questions and answers (in alpha order): Arpakorn Boonkongchuen Robert Kiessling "Ronnie B. Kon" Alain Martineau Barton.Bruce@camb.com (Barton F. Bruce / CCA) Bill Miskovetz Charley Kline Dave Katz Eriks Rugelis Howard C. Berkowitz, PSC International, Jim Forster John Wright Pete Siemsen Phillip Remaker Ran Atkinson Robert Kiessling Sanjay Rungta~ Sean McGrath Srinivas Vegesna Steve Cunningham Warren Lavallee William "Chops" Westfield atkinson@sundance.itd.nrl.navy.mil (Ran Atkinson) bpinsky@cisco.com (Bruce Pinsky) buk@taz.de ($ Burkhard Kohl) fred@cisco.com (Fred Baker) jerry@ksu.ksu.edu (Jerry Anderson) jhawk@panix.com (John Hawkinson) john@cisco.com (John Wright) john@gulfa.ods.gulfnet.kw (John Temples) paul@hawksbill.sprintmrn.com (Paul Ferguson) peter@ulisse.rhein-main.de (Peter Radig) tli@cisco.com (Tony Li) tom@park.uvsc.edu (Thomas R. Kimpton) vikas@Tudor.Com (Vikas Aggarwal) warner@cats.ucsc.edu (Jim Warner)

Last-modified: Mon, 22 Jan 2001 18:57:39 GMT
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