From: Arvinb@comcast.net
Date: Sat Dec 13 2003 - 14:53:53 GMT-3
Richard
I think original question was to advertise the summary address only when
both the longer prefixes exists. By default router keep on advertising the
summary address until it has a single longer prefix route in the routing
table. It stops advertising summary-address by defualt if it doesn't have
any longer prefix in routing table.
Conditional advetisement is BGP will advertise the summary-address when
router looses some prefix specified in non-exist map. How about to use this.
router bgp xxxx
aggregate-address 199.10.111.0 255.255.255.0 summary-only
!
neighbor x.x.x.x advertise-map m1 non-exist-map m2
route-map m1 permit 10
match ip address 1
route-map m2 deny 10
match ip address 2
access-list 1 permit 199.10.111.0 0.0.0.255
access-list 2 permit 199.10.111.160 0.0.0.7
access-list 2 permit 199.10.111.168 0.0.0.7
Arivnd
----- Original Message -----
From: <vdadlaney@comcast.net>
To: "Richard Davidson" <rich@myhomemail.net>
Cc: "groupstudy" <ccielab@groupstudy.com>
Sent: Saturday, December 13, 2003 11:12 AM
Subject: Re: BGP summary address
> Hi Richard,
>
> Are you sure you want to advertise a /24 for these routes. I personally
would aggregate to 199.10.111.160 255.255.255.240. Than as per your
requirements you can do a aggregate-address 199.10.111.160 255.255.255.240
summary-only or if you want the more specifics than remove the summary-only.
Once that is done than u can use a distribute-list on the neighbor statement
to the ebgp peers to deny the more specific routes if you have not used the
summary-only option and allow only the summary to your ebgp peers. Ofcourse
if you want to send a /24 than you can aggregate to that and follow the same
method. I think that would work. If anyone thinks this might not work than
please do correct me. Thanks
>
> Regards,
>
> Vikram
> > I need to send a summary address from two bgp routers
> > in one as to two other AS numbers. I need to only
> > send the summary to the remote AS numbers if the local
> > router knows about all of the local routes that fall
> > under the summary. Is this possible. Basically, send
> > 199.10.111.0/24 if; 199.10.111.160/29 and
> > 199.10.111.168/29 exists.
> >
> > Thanks for the support
> > Rich
> >
> > =====
> > Richard Davidson
> > Yahoo IM: r1davidson
> > e-mail rich@myhomemail.net
> >
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