RE: BGP filtering

Rob,

You're correct in the re-use and multiple options part, but the processing of filtering and attributes are different when its inbound vs outbound.

Inbound it's route-map, filter-list, prefix-list / distribute-list. Outbound is the opposite order.

http://www.cisco.com/en/US/tech/tk365/technologies_q_and_a_item09186a00800949e8.shtml#one

-ryan

-----Original Message-----
From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of robclav_at_gmail.com
Sent: Tuesday, June 23, 2009 8:19 AM
To: Evan Weston; 'Cisco certification'
Subject: Re: BGP filtering

Hi Evan,
Basically all related to route-map is proccessed before than a prefix-list by one hand, and by the other hand you will have a multiples options later if they ask you to modify this match in any way. For instance a conditional advertisement.
I hope this help,
Robclav

BlackBerry de movistar, allm donde estis esta tu oficin@

-----Original Message-----
From: "Evan Weston" <evan_weston_at_hotmail.com>

Date: Tue, 23 Jun 2009 20:42:52
To: 'Cisco certification'<ccielab_at_groupstudy.com>
Subject: BGP filtering

G'day all,

Just wondering if there's a difference between these two methods of
filtering besides the obvious i.e one way is a route-map and the other is a
prefix list. I ask because some vendor workbooks seem to prefer the
route-map method in their solution guides.

ip prefix-list AGGREGATE1 seq 5 deny 2.2.0.0/22

ip prefix-list AGGREGATE1 seq 10 permit 0.0.0.0/0 le 32

neighbour x.x.x.x prefix-list AGGREGATE1 out

ip prefix-list AGGREGATE2 seq 5 permit 2.2.0.0/22

!

route-map BGP_OUT deny 10

 match ip address prefix-list AGGREGATE2

!

route-map BGP_OUT permit 20

neighbour x.x.x.x route-map BGP_OUT out

Evan

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Received on Tue Jun 23 2009 - 09:02:19 ART