Filtering incoming BGP routes

From: Eddie Jobson (ejobson@xxxxxxxxxxxxx)
Date: Thu Nov 16 2000 - 14:34:39 GMT-3


   
ExtRouter--------------------------R4-----------------------------R5
EBGP----------------------------EBGP/IBGP-----------------------IBGP
AS254-----------------------------AS1----------------------------AS1
197.65.5.0 advertised only wants 197
150.200.1.0 advertised doesn't want 150

If anyone can understand the diag above, this is what I am trying to
achieve. An external AS (254) is advertising routes 197.65.5.0/24 &
150.200.1.0/24 to my AS#1. I receive these on R4 and pass them through
to R5 through IBGP, fine.

What I am having trouble doing though is, I want to block the 150
updates on the interface (eth0) or in the bgp routing process by either
using a distribute list, route map, ip access-group or whatever. Then
once the 150 route is filtered out and the 197 route is in the routing
table of R4 I want to set it's local preference and weight to 300, so
that when it is shown in R5's table these metrics are seen.

I have tried for the last two days using a combination of the following
commands and refering to Caslow and Hutnik, but still no joy. If anyone
can help I would appreciate it.

Thanks in advance.

Eddie.

P.S. Where is there a good reference list for regular expressions?

Some commands tried below (in no particular order)..............

route-map bgp
 set local-preference 300
 set weight 300
 match ip address 100

route-map bgpin permit 1
 match ip address 100

access-list 100 permit tcp 197.65.5.0 0.0.0.255 eq bgp any

ip access-group 100 in
distribute-list 100 in/out

route-map AS254 permit 10
 match as-path 1
 set local-preference 300
 set weight 300

ip as-path access-list 1 permit _254$
ip as-path access-list 1 permit 254$



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