I think routerB don't have a route to go back to routerC (172.17.x.x) so the reply could not get back to C. Check the routing table on B or turn on "deb ip icmp" on B and ping again from C. You need a network statement like "network 172.17.1.0" or "redistribute connected" on router C.
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Hunt Lee Sent: Saturday, June 08, 2002 4:52 PM To: [EMAIL PROTECTED] Subject: BGP scenario (a bit lenghty - sorry) [7:46131] Hi group, RotuerC ----------------- RouterA ---------------- RouterB On p9 of BGP 4 Command & Configuration Handbook (by Parkhurst), I follow the exercise on Aggregating the BGP Learning Routes, everything seems well except I can't ping from Router C to any of the 4 Loopback Interfaces I created on Router B, even though I can see the routes fine on both Router C's BGP table and Routing Table: RouterC>sh ip bgp BGP table version is 6, local router ID is 172.17.1.2 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path *> 172.16.0.0/24 172.17.1.1 0 1 2 i *> 172.16.0.0/22 172.17.1.1 0 1 i *> 172.16.1.0/24 172.17.1.1 0 1 2 i *> 172.16.2.0/24 172.17.1.1 0 1 2 i *> 172.16.3.0/24 172.17.1.1 0 1 2 i RouterC> RouterC>sh ip route Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate default U - per-user static route Gateway of last resort is not set 172.16.0.0/16 is variably subnetted, 5 subnets, 2 masks B 172.16.0.0/22 [20/0] via 172.17.1.1, 00:00:55 B 172.16.0.0/24 [20/0] via 172.17.1.1, 02:19:56 B 172.16.1.0/24 [20/0] via 172.17.1.1, 02:19:56 B 172.16.2.0/24 [20/0] via 172.17.1.1, 02:19:56 B 172.16.3.0/24 [20/0] via 172.17.1.1, 02:19:56 172.17.0.0/24 is subnetted, 1 subnets C 172.17.1.0 is directly connected, Serial0 RouterC> When I tried to do a trace to say 172.16.0.1 (which is one of the loopback interface created on Router B), the packets was stuck on Router A RouterC>trace 172.16.0.1 Type escape sequence to abort. Tracing the route to 172.16.0.1 1 RouterA (172.17.1.1) 16 msec 16 msec 20 msec 2 * * * 3 However, on Router A, I can ping fine to all 4 loopback interfaces advertised by Router B:- RouterA#ping 172.16.0.1 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 172.16.0.1, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 32/32/32 ms RouterA#ping 172.16.1.1 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 172.16.1.1, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 32/32/32 ms RouterA#ping 172.16.2.1 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 172.16.2.1, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 28/54/148 ms RouterA# So if Router A can get to the Loopback interfaces advertised by Router B, and Router C have got the routes in the Routing Table, why can't Router C trace or ping to Router B's Loopback interfaces?? Please find attached a copy of the configs for the 3 routers:- RouterC#sh run Building configuration... Current configuration: ! version 11.1 service timestamps debug datetime msec show-timezone service timestamps log datetime msec show-timezone service udp-small-servers service tcp-small-servers ! hostname RouterC ! enable secret 5 $1$R1vV$Ld5F0ueggoSyb4z/goBGF. ! ! interface Ethernet0 no ip address ! interface Serial0 ip address 172.17.1.2 255.255.255.0 ! interface Serial1 no ip address ! router bgp 65530 neighbor 172.17.1.1 remote-as 1 ! ip host RouterA 172.17.1.1 ip classless logging buffered ! line con 0 line aux 0 line vty 0 4 password cisco login ! end RouterC# ---------------------------------------------------------------------------- --------------------------------------------------------- RouterA#sh run Building configuration... Current configuration : 907 bytes ! version 12.2 no service single-slot-reload-enable service timestamps debug uptime service timestamps log uptime no service password-encryption ! hostname RouterA ! logging rate-limit console 10 except errors enable secret 5 $1$hCDv$aQ/xa.CZ7YloCaNRpAaI90 ! ip subnet-zero no ip finger no ip domain-lookup ip host RouterC 172.17.1.2 ip host RouterB 10.1.1.2 ! no ip dhcp-client network-discovery ! ! ! ! interface Ethernet0 no ip address ! interface Serial0 ip address 172.17.1.1 255.255.255.0 clockrate 64000 ! interface Serial1 ip address 10.1.1.1 255.255.255.252 clockrate 64000 ! router bgp 1 bgp log-neighbor-changes aggregate-address 172.16.0.0 255.255.252.0 neighbor 10.1.1.2 remote-as 2 neighbor 172.17.1.2 remote-as 65530 ! ip kerberos source-interface any ip classless ip http server ! ! ! line con 0 transport input none line 1 16 line aux 0 line vty 0 4 password cisco login ! end RouterA# ---------------------------------------------------------------------------- --------------------------------------------------------------- RouterB#sh run Building configuration... Current configuration: ! version 12.0 service timestamps debug uptime service timestamps log uptime no service password-encryption ! hostname RouterB ! enable secret 5 $1$zNVg$hD/CjofG0d4SosB6/7.1I1 ! ip subnet-zero no ip domain-lookup ip host RouterA 10.1.1.1 ! ! ! interface Loopback0 ip address 172.16.0.1 255.255.255.0 ip directed-broadcast ! interface Loopback1 ip address 172.16.1.1 255.255.255.0 ip directed-broadcast ! interface Loopback2 ip address 172.16.2.1 255.255.255.0 ip directed-broadcast ! interface Loopback3 ip address 172.16.3.1 255.255.255.0 ip directed-broadcast ! interface Ethernet0 no ip address no ip directed-broadcast ! interface Serial0 ip address 10.1.1.2 255.255.255.252 ip directed-broadcast ! interface Serial1 no ip address no ip directed-broadcast ! interface BRI0 no ip address no ip directed-broadcast ! router bgp 2 network 172.16.0.0 mask 255.255.255.0 network 172.16.1.0 mask 255.255.255.0 network 172.16.2.0 mask 255.255.255.0 network 172.16.3.0 mask 255.255.255.0 neighbor 10.1.1.1 remote-as 1 no auto-summary ! ip classless ! ! line con 0 transport input none line aux 0 line vty 0 4 password cisco login ! end RouterB# Thanks in advance, Hunt Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=46132&t=46131 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
