From: trust.hogo@sarcom.com
Date: Tue Feb 18 2003 - 19:21:14 GMT-3
The aggregate-address statement is correct. The route will be advertised as
if you are the originator but it will also indicate that's its missing info.
I hope the following will help clarify. From The Command Reference guide:
Usage Guidelines
You can implement aggregate routing in BGP and multiprotocol BGP either by
redistributing an aggregate route into BGP or multiprotocol BGP, or by using
this conditional aggregate routing feature.
Using the aggregate-address command with no keywords will create an
aggregate entry in the BGP or multiprotocol BGP routing table if any
more-specific BGP or multiprotocol BGP routes are available that fall in the
specified range. The aggregate route will be advertised as coming from your
autonomous system and will have the atomic aggregate attribute set to show
that information might be missing. (By default, the atomic aggregate
attribute is set unless you specify the as-set keyword.)
Using the as-set keyword creates an aggregate entry using the same rules
that the command follows without this keyword, but the path advertised for
this route will be an AS_SET consisting of all elements contained in all
paths that are being summarized. Do not use this form of the
aggregate-address command when aggregating many paths, because this route
must be continually withdrawn and reupdated as autonomous system path
reachability information for the summarized routes changes.
Thanks
Trusth
-----Original Message-----
From: Peter van Oene [mailto:pvo@usermail.com]
Sent: Tuesday, February 18, 2003 12:54 PM
To: ccielab@groupstudy.com
Subject: RE: GBP Question
At 09:22 AM 2/18/2003 -0500, Cameron, John wrote:
>Use the following on Router B:
>
>aggregate-address 150.50.31.0 255.255.255.0 summary-only
For what its worth, this is an entirely different route than the original
path. Why not just filter the incoming route and announce your own if we
are taking that much liberty? Of note, I'm not entirely sure that the
aggregate-address command will accept a prefix of the same depth for a
contributor. Indeed, if it did, this would seem broken to me.
>This will remove Router A as the originator of the prefix
>an make it "look" as if Router C ownes the prefix.
This will create two routes in the network where one previously
existed. In my books, this wouldn't be a valid answer to the question,
then again I expect I wouldn't ask for BGP to be broken in the question.
Pete
>HTH,
>JDC
>
>
>-----Original Message-----
>From: love cisco [mailto:love_cisco@hotmail.com]
>Sent: Tuesday, February 18, 2003 5:07 AM
>To: ccielab@groupstudy.com
>Subject: GBP Question
>
>
>I have a question about filtering BGP As number in AS path table.
>
>Router A has a ip address 150.50.31.1/24 distributed in bgp AS100. In
>Router C bgp table, you will see the 150.50.31.0 network as-path is
>"200 100". My question is how to config bgp in router B to filtering as
>path number 100. So router C will only 150.50.31.0 network as-path is
>"200"?
>
> ------------ ------------ ------------
> | Router A |------------| Router B |--------------| Router C |
> | AS 100 | | AS 200 | | AS 300 |
> ------------ ------------ ------------
> 150.50.31.1/24
>
>_________________________________________________________________
>OmSCJ@=gIOWn4s5D5gWSSJ<~O5M3!* MSN Hotmail!# http://www.hotmail.com
This archive was generated by hypermail 2.1.4 : Sat Mar 01 2003 - 11:06:27 GMT-3