From: Sergey (public@svlp.net)
Date: Tue Sep 25 2007 - 04:37:05 ART
There are two routers in AS300 with enabled synchronization, both router have bgp peering with as 100.
R1(as100) --- R3(as300) --- R4(as300)---R2 (as100)
The restriction says that R4 should prefer R3 for any external routes, so I simply set on R4 weight = 2000 to R3.
But I've discovered one moment. If session between R4 & R3 comes first, everything works fine. But if
session between R4 & R3 comes after R4 & R2 session than R4 thinks that routes from R3 are
not synced (because no IGP routes in routing table) and prefer routes from R2 in spite of that R3 has weight = 2000.
R4(config-router)#do sh ip bgp 70.70.70.0
BGP routing table entry for 70.70.70.0/24, version 6
Paths: (2 available, best #2, table Default-IP-Routing-Table)
Flag: 0x960
Advertised to update-groups:
1 2
100 700
172.16.36.6 (metric 20) from 172.16.34.3 (172.16.103.1)
Origin incomplete, metric 0, localpref 100, weight 2000, valid, internal, not synchronized
100 700
172.16.124.1 (metric 64) from 172.16.124.5 (172.16.102.1)
Origin incomplete, localpref 100, valid, external, best
I want that R4 always select routes from R3 in spite of what session comes first. What is the best way to accomplish it?
This archive was generated by hypermail 2.1.4 : Sat Oct 06 2007 - 12:01:15 ART