[c-nsp] adjusting AD based on route tag/community?

[Andrey A. Ryazanov]

You can adjust AD locally

router bgp 12345
distance bgp 180 200 200

router ospf 1
distance 110

You can't propagate AD via routing protocols to other routers.

You can't alter AD via route-maps.

You can't avoid more specific routing policy.

Well ... there's no luck in this life :D

P.S. There're certainly some well-known methods exist to resolve your problems. Just 
specify what exactly your problems are.

Cheers! ;)

Andrey Ryazanov
Digital Network JSC
+7 095 723 8332 ext. 203

---------- Original Message -----------
From: bj at zuto.de (Rainer Clasen)
To: Discussion for Network Service Provider <cisco-nsp at puck.nether.net>
Sent: Tue, 14 Jun 2005 16:14:56 +0200
Subject: [c-nsp] adjusting AD based on route tag/community?

> Hello,
> 
> rethinking some of our setups I'm currently wondering if there is a way
> to adjust the administrative distance of routes learned through OSPF/BGP.
> 
> That'd help me in certain scenarios:
> - mutual redistribution, prefering some routes on each redistribution
>   point
> - two level backups (i.e. if primary link and first backup fails, kick in
>   the second one)
> - initiating callback for a backup dialin on router A, while the client
>   calls you on router B
> 
> The Idea is to have some special backup routes configured with a tag. This
> tag is propagated through OSPF or BGP and used to set the AD on the other
> routers. (OT: reading juniper docs I got the impression, you can play such
> dirty tricks with the color)
> 
> I've also tried to abuse BGP weights for this, but had no luck. If you
> redistribute routes into BGP, you have to set their AD > 200 to give BGP
> the chance to override them. On the other hand you have to set the AD <
> 200 if you want a newly installed route to be considered for installation
> if there is a BGP route active ...
> 
> Somehow I'd like to avoid using more-specific routes for the primary link
> to overrule all backups ...
> 
> Rainer
> 
> -- 
> KeyID=759975BD fingerprint=887A 4BE3 6AB7 EE3C 4AE0  B0E1 0556 E25A 7599 75BD
> _______________________________________________
> cisco-nsp mailing list  cisco-nsp at puck.nether.net
> https://puck.nether.net/mailman/listinfo/cisco-nsp
> archive at http://puck.nether.net/pipermail/cisco-nsp/
------- End of Original Message -------