From: Hunt Lee (ciscoforme3@xxxxxxxxxxxx)
Date: Sun Jun 16 2002 - 08:05:07 GMT-3
Okay folks, starting off some late nite studying and just noticed something
weird. Got a Confederation setup like:
150.150.150.0/24---RTA ---RTB ---RTD---RTF
| |
RTC RTE
RTA, B, C, D, & E are in a Confederation called AS 1, in which:-
RTA is sub-AS 65530
RTB & RTC are both in sub-AS 65531
RTD & RTE are both in sub-AS 65532
RTF is in AS 2
RTB, C, D & E are running OSPF as IGP. And OSPF is being redistributed into
BGP at RTB.
The network 150.150.150.0/24 is being advertised into BGP by BGP "network"
command on RTA.
Ok, here is the thing. The 150.150.150.0/24 network is being seen by RTA, RTB,
RTD, & RTF. I could ping 150.150.150.1 from these four routers. However, it
can't be seen by RTC & RTE (shown as follows). But when I put "no
synchronization" on the middle four routers (RTB, RTC, RTD, & RTE), then
everything becomes fine again... I thought since I used IGP (OSPF), and if
the router can see the EBGP Next-Hop (193.16.0.2) in their routing table, then
the synch. rule shouldn't apply anymore.
Am I missing something here?
RouterC#sh ip bgp
BGP table version is 4, local router ID is 172.16.0.2
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
* i150.150.150.0/24 193.16.0.2 0 100 0 (65530) i
<-----193.16.0.2 is the Serial int of RTA
*>i172.16.0.0/30 172.16.0.1 0 100 0 ?
* i172.16.0.12/30 172.16.0.18 30 100 0 ?
*>i172.16.0.16/30 172.16.0.1 0 100 0 ?
*>i193.16.0.0/30 172.16.0.1 0 100 0 ?
* i193.16.0.8/30 172.16.0.18 0 100 0 (65532) i
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
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, * - candidate default
U - per-user static route, o - ODR
Gateway of last resort is not set
172.16.0.0/30 is subnetted, 3 subnets
O 172.16.0.16 [110/128] via 172.16.0.1, 01:35:04, Serial1
O 172.16.0.12 [110/192] via 172.16.0.1, 01:35:04, Serial1
C 172.16.0.0 is directly connected, Serial1
193.16.0.0/30 is subnetted, 1 subnets
O 193.16.0.0 [110/74] via 172.16.0.1, 01:35:04, Serial1
RouterC#
RouterC#ping 193.16.0.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 193.16.0.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 28/32/36 ms
RouterC#
Thanks all!
Hunt
http://www.sold.com.au - SOLD.com.au
- Find yourself a bargain!
This archive was generated by hypermail 2.1.4 : Tue Jul 02 2002 - 08:12:33 GMT-3