From: Carlos (cchorao@xtra.co.nz)
Date: Fri Apr 18 2003 - 01:02:05 GMT-3
Kevin ,
Aggregate-address 192.168.2.0 255.255.255.0 summary-only < -- This command
only summarizes more specific routes. Since there arent any no summary is
generated.
One the ways I got the 192.168.2.0 prefix to appear to originate from "as
400" is with the use of static route ( If intructions forbid statics then
this is not a valid option )
ip route 192.168.2.0 255.255.255.0 a.b.c.d <--- next hop addr to as
100
router bgp 200
redis static
Carlos Chorao (CCIE # 11351 R&S)
Telecom New Zealand - Advanced Solutions Group : Network Design and Security
----- Original Message -----
From: "Ouellette, Tim" <tim.ouellette@eds.com>
To: "'Corbin, Kevin'" <Kevin.Corbin@LibertyMutual.com>
Cc: <ccielab@groupstudy.com>
Sent: Friday, April 18, 2003 1:29 PM
Subject: RE: BGP AS Path Manipulation
> I think the problem might be that you already have a 192.168.2.0/24 in the
> bgp table and if you turn on debugging you'll probably see a message that
> says "cannot aggregate and aggregate". What you might want to do is deny
> the 192.168.2.0/24 from coming in from your bgp neighbor into your bgp
table
> and then try your aggregate address command. Not sure if it'll work but
> give it a shot. This is probably the reason your /23 works because it's a
> new aggregate.
>
> Tim
>
> -----Original Message-----
> From: Corbin, Kevin [mailto:Kevin.Corbin@LibertyMutual.com]
> Sent: Thursday, April 17, 2003 12:42 PM
> To: ccielab@groupstudy.com
> Subject: BGP AS Path Manipulation
>
>
> If I am aggregating a range of routes w/o the as-set command it will
"hide"
> the as path information from which is was learned, but is there a way to
do
> this for a single route
>
> Example :
>
> 192.168.1.0
> 192.168.2.0 AS100-------AS200------AS300----AS400----AS500
> 192.168.3.0
> If I am receiving 192.168.1.0, 192.168.2.0, 192.168.3.0 with as path 100
200
> 300 then
>
> Router bgp 400
> Aggregate-address 192.168.0.0 255.255.252 summary-only
>
> Will make the aggregate appear as if it was origninated from as 400.
>
> But if I want to do this to just a single /24....
>
> Aggregate-address 192.168.2.0 255.255.255.0 summary-only
>
> Seems to still maintain the complete as path information, is this just
> because I'm not really "aggregating" or is there something else I'm
missing.
> I have noticed that if
>
> I change the aggregate mask to 255.255.254.0 then it works, I guess the
> short version of my question is this, How would I make a single /24 appear
> to have originated from AS400 without changing the length of the prefix?
>
>
> TIA
> Kevin
This archive was generated by hypermail 2.1.4 : Thu May 01 2003 - 13:35:57 GMT-3