From: Joe Chang (changjoe@earthlink.net)
Date: Tue Jun 01 2004 - 20:20:05 GMT-3
Two rules of BGP advertisement may apply in this case:
- BGP advertises only routes that are are in its local routing information
base (local-RIB)
- BGP never advertistses routes learned from an internal peer to another
internal peer.
Was your alteration to BGP 200 followed by R3 discontinuing advertisements
to R2? If so:
- Were the missing subnets still in R3's local-RIB?
- If they are present in the local-RIB, is their source R1 or BB2?
----- Original Message -----
From: "Peng Zheng" <zpnist@yahoo.com>
To: <ccielab@groupstudy.com>
Sent: Tuesday, June 01, 2004 6:27 PM
Subject: BGP local-preference
> Three Router, R1, R2, R3, all in AS 100. Fully meshed.
>
> R1 connect to BB1 (in AS 200),
> R3 connect to BB2 (also in AS 200).
>
> They both receive some prefix, R3 also generates a
> summary route. Ask R1 make R1 and R2 to prefer R1 to
> subnet, and prefer R3 to the summary.
>
> Before I configure, R1, R2 and R3 can see all routes
> in their BGP table, each of them are from both R1 and
> R3.
>
> Then I set up those subnet from BB1 (on R1) with
> local-preference 200, Now from R2 and R1, I can only
> see (in BGP table) those subnets from R1. If I
> shutdown the peer between R2 and R1, R2 can see the
> subnets from R3. Why I can not see those subnets
> from R3 on R1 and R2 after I set the local-preference?
>
>
>
>
>
>
>
>
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This archive was generated by hypermail 2.1.4 : Sat Jul 03 2004 - 19:40:31 GMT-3