From: tlarus@cox.net
Date: Thu Apr 17 2003 - 10:50:48 GMT-3
This is just a wild guess, but perhaps you have split horizon disabled on one interface in the RIP domain and routes are being bounced back from that interface and poisoning the real RIP routes.
Tom Larus
>
> From: Hunt Lee <huntl@webcentral.com.au>
> Date: 2003/04/17 Thu AM 08:34:02 EDT
> To: "'ccielab@groupstudy.com'" <ccielab@groupstudy.com>
> Subject: BGP route disappearing, please help!!
>
> Hi Team,
>
> ... - r6 --- r13 -- Loopback 0 (198.5.51.1/24)
> -- Loopback 1 (198.5.52.1/24)
> -- Loopback 2 (198.5.53.1/24)
> -- Loopback 0 (198.5.54.1/24)
>
> The link between the routers are EBGP, and they are also talking in RIPv1.
>
> ...and there are some OSPF routers on the left of r6. And r6 is part of a
> BGP confederation with the routers on the left.
>
> r13's interface (to r6) - 200.100.100.13 /24
>
> All 4 loopbacks are advertised by RIPv1 as well as BGP.
>
> Ok. What I don't understand is that when r6 first boots up, it can see the
> 4 BGP routes fine, & can ping fine also...
>
> r6#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
> N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
> 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, ia - IS-IS inter
> area
> * - candidate default, U - per-user static route, o - ODR
> P - periodic downloaded static route
>
> Gateway of last resort is not set
>
> C 200.100.100.0/24 is directly connected, Ethernet0
> R 172.16.0.0/16 [120/2] via 200.100.100.13, 00:00:05, Ethernet0
> B 198.5.51.0/24 [20/0] via 200.100.100.13, 00:01:27
> B 198.5.53.0/24 [20/0] via 200.100.100.13, 00:01:27
> B 198.6.53.0/24 [200/0] via 150.10.2.2, 00:00:57
> B 198.5.52.0/24 [20/0] via 200.100.100.13, 00:01:27
> B 198.5.54.0/24 [20/0] via 200.100.100.13, 00:01:27
> 150.10.0.0/16 is variably subnetted, 13 subnets, 5 masks
> O IA 150.10.20.0/25 [110/129] via 150.10.60.5, 00:00:05, Serial0
> O IA 150.10.10.0/28 [110/128] via 150.10.60.5, 00:00:05, Serial0
> O E2 150.10.4.0/24 [110/20] via 150.10.60.5, 00:00:05, Serial0
> C 150.10.6.0/24 is directly connected, Loopback0
> O IA 150.10.5.5/32 [110/65] via 150.10.60.5, 00:00:05, Serial0
> O IA 150.10.2.2/32 [110/129] via 150.10.60.5, 00:00:05, Serial0
> O IA 150.10.1.1/32 [110/129] via 150.10.60.5, 00:00:05, Serial0
> O E2 150.10.3.0/24 [110/20] via 150.10.60.5, 00:00:05, Serial0
> C 150.10.60.0/24 is directly connected, Serial0
> O IA 150.10.50.0/24 [110/128] via 150.10.60.5, 00:00:05, Serial0
> O E2 150.10.45.0/24 [110/20] via 150.10.60.5, 00:00:05, Serial0
> O E2 150.10.40.0/24 [110/20] via 150.10.60.5, 00:00:05, Serial0
> C 150.10.65.0/30 is directly connected, BRI0
> B 198.6.48.0/21 [200/0] via 150.10.2.2, 00:00:59
> r6#
>
>
> r6#ping 198.5.51.1
>
> Type escape sequence to abort.
> Sending 5, 100-byte ICMP Echos to 198.5.51.1, timeout is 2 seconds:
> !!!!!
> Success rate is 100 percent (5/5), round-trip min/avg/max = 4/4/8 ms
> r6#ping 198.5.52.1
>
> Type escape sequence to abort.
> Sending 5, 100-byte ICMP Echos to 198.5.52.1, timeout is 2 seconds:
> !!!!!
> Success rate is 100 percent (5/5), round-trip min/avg/max = 4/4/8 ms
> r6#ping 198.5.53.1
>
> Type escape sequence to abort.
> Sending 5, 100-byte ICMP Echos to 198.5.53.1, timeout is 2 seconds:
> !!!!!
> Success rate is 100 percent (5/5), round-trip min/avg/max = 1/3/4 ms
> r6#ping 198.5.54.1
>
> Type escape sequence to abort.
> Sending 5, 100-byte ICMP Echos to 198.5.54.1, timeout is 2 seconds:
> !!!!!
> Success rate is 100 percent (5/5), round-trip min/avg/max = 4/4/4 ms
> r6#
>
>
> r6#sh ip bgp
> BGP table version is 11, local router ID is 150.10.6.6
> 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
> *> 150.10.3.0/24 150.10.10.3 50 100 0 (250) i
> *> 150.10.20.0/25 150.10.10.3 100 100 0 (250) i
> *> 150.10.45.0/24 150.10.40.4 100 100 0 (250) i
> *> 150.10.50.0/24 150.10.5.5 50 100 0 (250) i
> *> 198.5.51.0 200.100.100.13 0 1000 130 i
> *> 198.5.52.0 200.100.100.13 0 1000 130 i
> *> 198.5.53.0 200.100.100.13 0 1000 130 i
> *> 198.5.54.0 200.100.100.13 0 1000 130 i
> *> 198.6.48.0/21 150.10.2.2 100 0 (250 8) i
> *> 198.6.53.0 150.10.2.2 0 100 0 (250 8) 1000 i
> r6#
>
> But if you wait for around 3 mins, those 4 routes would say "...is possibly
> down"!!!
>
>
> r6#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
> N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
> 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, ia - IS-IS inter
> area
> * - candidate default, U - per-user static route, o - ODR
> P - periodic downloaded static route
>
> Gateway of last resort is not set
>
> C 200.100.100.0/24 is directly connected, Ethernet0
> R 172.16.0.0/16 [120/2] via 200.100.100.13, 00:00:02, Ethernet0
> B 198.5.51.0/24 is possibly down, routing via 200.100.100.13
> B 198.5.53.0/24 is possibly down, routing via 200.100.100.13
> B 198.6.53.0/24 [200/0] via 150.10.2.2, 00:05:54
> B 198.5.52.0/24 is possibly down, routing via 200.100.100.13
> B 198.5.54.0/24 is possibly down, routing via 200.100.100.13
> 150.10.0.0/16 is variably subnetted, 13 subnets, 5 masks
> O IA 150.10.20.0/25 [110/129] via 150.10.60.5, 00:05:02, Serial0
> O IA 150.10.10.0/28 [110/128] via 150.10.60.5, 00:05:02, Serial0
> O E2 150.10.4.0/24 [110/20] via 150.10.60.5, 00:05:02, Serial0
> C 150.10.6.0/24 is directly connected, Loopback0
> O IA 150.10.5.5/32 [110/65] via 150.10.60.5, 00:05:02, Serial0
> O IA 150.10.2.2/32 [110/129] via 150.10.60.5, 00:05:03, Serial0
> O IA 150.10.1.1/32 [110/129] via 150.10.60.5, 00:05:03, Serial0
> O E2 150.10.3.0/24 [110/20] via 150.10.60.5, 00:05:03, Serial0
> C 150.10.60.0/24 is directly connected, Serial0
> O IA 150.10.50.0/24 [110/128] via 150.10.60.5, 00:05:03, Serial0
> O E2 150.10.45.0/24 [110/20] via 150.10.60.5, 00:05:03, Serial0
> O E2 150.10.40.0/24 [110/20] via 150.10.60.5, 00:05:03, Serial0
> C 150.10.65.0/30 is directly connected, BRI0
> B 198.6.48.0/21 [200/0] via 150.10.2.2, 00:05:56
> r6#
>
>
> r6#sh ip bgp
> BGP table version is 11, local router ID is 150.10.6.6
> 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
> *> 150.10.3.0/24 150.10.10.3 50 100 0 (250) i
> *> 150.10.20.0/25 150.10.10.3 100 100 0 (250) i
> *> 150.10.45.0/24 150.10.40.4 100 100 0 (250) i
> *> 150.10.50.0/24 150.10.5.5 50 100 0 (250) i
> *> 198.5.51.0 200.100.100.13 0 1000 130 i
> *> 198.5.52.0 200.100.100.13 0 1000 130 i
> *> 198.5.53.0 200.100.100.13 0 1000 130 i
> *> 198.5.54.0 200.100.100.13 0 1000 130 i
> *> 198.6.48.0/21 150.10.2.2 100 0 (250 8) i
> *> 198.6.53.0 150.10.2.2 0 100 0 (250 8) 1000 i
> r6#
>
>
> r6#ping 198.5.51.1
>
> Type escape sequence to abort.
> Sending 5, 100-byte ICMP Echos to 198.5.51.1, timeout is 2 seconds:
> .....
> Success rate is 0 percent (0/5)
> r6#sh ip route 198.5.51.1
> Routing entry for 198.5.51.0/24
> Known via "bgp 6", distance 20, metric 4294967295 (inaccessible)
> Tag 130, type external
> Last update from 200.100.100.13 00:04:10 ago
> Hold down timer expires in 120 secs
>
> r6#
>
> And here ere are the configs for the 2 routers ;)
>
> For r6:-
>
> interface Ethernet0
> ip address 200.100.100.6 255.255.255.0
> ip pim sparse-mode
>
> router ospf 1
> log-adjacency-changes
> area 5 authentication message-digest
> redistribute rip metric 65 metric-type 1 subnets route-map Even
> network 150.10.6.6 0.0.0.0 area 5
> network 150.10.60.6 0.0.0.0 area 5
> network 150.10.65.2 0.0.0.0 area 5
> !
> router rip
> redistribute ospf 1 metric 2
> passive-interface BRI0
> network 200.100.100.0
>
> router bgp 6
> no synchronization
> bgp log-neighbor-changes
> bgp confederation identifier 22
> bgp confederation peers 250
> neighbor 150.10.5.5 remote-as 250
> neighbor 150.10.5.5 ebgp-multihop 255
> neighbor 150.10.5.5 update-source Loopback0
> neighbor 150.10.5.5 next-hop-self
> neighbor 200.100.100.13 remote-as 130
> neighbor 200.100.100.13 route-map Weight in
> neighbor 200.100.100.13 filter-list 2 out
> no auto-summary
>
> ip as-path access-list 2 permit ^$
> ip pim rp-address 150.10.5.5
>
> route-map Weight permit 10
> set weight 1000
>
> route-map Even permit 10
> match ip address 1
>
> access-list 1 permit 198.5.0.0 0.0.254.255
> access-list 1 permit 200.0.0.0 0.255.255.255
> access-list 1 permit 172.16.0.0 0.0.255.255
> access-list 1 permit 10.0.0.0 0.255.255.255
>
> ... and for r13:-
>
> interface Loopback0
> ip address 198.5.51.1 255.255.255.0
> !
> interface Loopback1
> ip address 198.5.52.1 255.255.255.0
> !
> interface Loopback2
> ip address 198.5.53.1 255.255.255.0
> !
> interface Loopback3
> ip address 198.5.54.1 255.255.255.0
>
> interface FastEthernet0/0
> ip address 200.100.100.13 255.255.255.0
> ip pim sparse-mode
> ip igmp join-group 224.0.5.5
> speed 100
> full-duplex
>
> router rip
> redistribute static metric 2
> network 198.5.51.0
> network 198.5.52.0
> network 198.5.53.0
> network 198.5.54.0
> network 200.100.100.0
> !
> router bgp 130
> bgp log-neighbor-changes
> network 198.5.51.0
> network 198.5.52.0
> network 198.5.53.0
> network 198.5.54.0
> neighbor 200.100.100.6 remote-as 22
> no auto-summary
>
> ip route 172.16.1.0 255.255.255.0 10.1.1.14
> !
> end
>
> Any help will be greatly appreciated.
>
> Regards,
> Hunt
This archive was generated by hypermail 2.1.4 : Thu May 01 2003 - 13:35:56 GMT-3