From: Peter (peter@cyscoexpert.com)
Date: Wed Feb 19 2003 - 00:31:10 GMT-3
The route-map is applied before the AS gets prepended, so your as-path ACL
should have ^$ if you want to tag all AS 4799 internal routes with the
no-export community or if you need to tag everything then you would not need
to use any as-path ACL, just tag everything in a single route-map sequence.
_____________________________
Peter
#7247 (R&S, Security)
CyscoExpert Corp.
4433 W. Touhy Ave. Suite 410
Lincolnwood, IL 60712
Phone (847) 674-3392
Toll Free (866) CyscoXP (297-2697)
Fax (847) 674-2625
----- Original Message -----
From: "pita40" <pita40@hotmail.com>
To: <ccielab@groupstudy.com>
Sent: Tuesday, February 18, 2003 6:30 PM
Subject: BGP & community
> I have a question from one of the commecial labs.
>
> Configure BGP such that BGP routes learned by AS 111 from AS 4799 are not
> passed onto their EBGP peers
>
> I used the first config with as-path. When I go to the bgp peer (BB1) to
look
> at the attribute for the routes it learned from R1 I get a shock that it
is
> not advertising to any peer.
> When I remove as-path statement I get not advertised to EBGP peer which is
the
> correct answer.
> Please help clarify why the routes are behaving like this.
>
> R1
>
> router bgp 65013
> bgp confederation identifier 4799
> bgp confederation peers 65053
> neighbor 150.50.33.33 remote-as 65013
> neighbor 150.50.33.33 update-source Loopback0
> neighbor 150.50.111.111 remote-as 111
> neighbor 150.50.111.111 send-community
> neighbor 150.50.111.111 route-map comm out
> no auto-summary
>
>
> ip as-path access-list 11 permit _4799_
>
>
> route-map comm permit 10
> match as-path 11
> set community no-export
> !
> route-map comm permit 20
>
> With the above config I get the following on BB1 with is nei
150.50.111.111
>
> bb1#sh ip bgp 133.133.133.0 255.255.255.0
> BGP routing table entry for 133.133.133.0/24, version 47
> Paths: (1 available, best #1)
> Not advertised to any peer
> 4799
> 150.50.111.1 from 150.50.111.1 (200.200.11.11)
> Origin incomplete, localpref 100, valid, external, best, ref 2
>
> When I remove the as-path command like this
>
> route-map comm permit 10
> set community no-export
>
> I get this on BB1
>
> bb1#sh ip bgp 133.133.133.0 255.255.255.0
> BGP routing table entry for 133.133.133.0/24, version 76
> Paths: (1 available, best #1, not advertised to EBGP peer)
> Not advertised to any peer
> 4799
> 150.50.111.1 from 150.50.111.1 (200.200.11.11)
> Origin incomplete, localpref 100, valid, external, best, ref 2
> Community: no-export
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