From: cciehksg (cciehksg@yahoo.com.sg)
Date: Wed Sep 12 2007 - 13:11:40 ART
Hi there
when building pure ibgp-ebgp network as below :
routes in R1 show up in R4's BGP table, but not in R4's routing table ?
but sometime the R1's route appear in R4's routing table for a while
and if we observe the bgp table, sometime the route shows as best(>)
and then the best status dissappeared
i also noticed that the bgp table version number keep incrementing
R1-------------------------------------R2----------------------------------------------R3-------------------------------------------R4
-
10.10.10.1 /8 __ 10.10.10.2 /8 __ 172.172.172.2 /16 __ 172.172.172.3 /16 __192.168.1.3 /24 __ 192.168.1.4 /24
R1 in AS 100
R2,R3,R4 in AS 200
R1
router bgp 100
nei 10.10.10.2 remote-as 200
net 10.0.0.0
no auto-summary
R2
router bgp 200
no sync
nei 10.10.10.1 remote-as 100
nei 172.172.172.3 remote-as 200
nei 192.168.1.4 remote-as 200
net 10.0.0.0
net 172.172.0.0
no auto-summary
R3
router bgp 200
no sync
nei 172.172.172.2 remote-as 200
nei 192.168.1.4 remote-as 200
net 172.172.0.0
net 192.168.1.0
no auto-summary
R4
router bgp 200
no sync
nei 172.172.172.2 remote-as 200
nei 192.168.1.3 remote-as 200
net 192.168.1.0
no auto-summary
R4#sh ip bgp
BGP table version is 29, local router ID is 192.168.1.4
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
*>i10.0.0.0 172.172.172.2 0 100 0 i
*>i172.172.0.0 172.172.172.2 0 100 0 i
* i 192.168.1.3 0 100 0 i
* i192.168.1.0 192.168.1.3 0 100 0 i
*> 0.0.0.0 0 32768 i
R4#sh ip ro
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, su - IS-IS summary, 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
B 172.172.0.0/16 [200/0] via 172.172.172.2, 00:00:56
B 10.0.0.0/8 [200/0] via 172.172.172.2, 00:00:56
C 192.168.1.0/24 is directly connected, Serial0/0
R4#sh ip bgp
BGP table version is 31, local router ID is 192.168.1.4
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
* i10.0.0.0 172.172.172.2 0 100 0 i
* i172.172.0.0 172.172.172.2 0 100 0 i
*>i 192.168.1.3 0 100 0 i
* i192.168.1.0 192.168.1.3 0 100 0 i
*> 0.0.0.0 0 32768 i
this is when the routes in R1 disappeared
R4#sh ip ro
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, su - IS-IS summary, 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
B 172.172.0.0/16 [200/0] via 192.168.1.3, 00:00:16
C 192.168.1.0/24 is directly connected, Serial0/0
R4#
try to add the next-hop-self command but it didn't help much
is it possible to make this topology works using only ibgp+ebgp ?
am i missing something here ?
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Real people. Real questions. Real answers. Share what you know.
This archive was generated by hypermail 2.1.4 : Sat Oct 06 2007 - 12:01:11 ART