nanog mailing list archives
RE: Tricky BGP into IGP Question
From: "Barry Raveendran Greene" <bgreene () cisco com>
Date: Tue, 23 Jan 2001 18:40:17 -0800
Hello Tim, I'm assuming that "1," "3," and "4" are separate AS numbers with "2a" and "2b" in the same as providing transit ....... given that ..... The BCP for redistributing BGP into the IGP is just _NOT_ to do it. Redistributing BGP into the IGP is a very dangerous thing to do. Besides, the problem you described below has nothing to do with "1" routes being in the IGP. They should not be in the IGP in the first place. The problem you are describing sounds just like a recursive lookup failure on "1's" next-hop information. The subnet between 1 and 2a is not in the IGP. Hence, when 1's routes get to 2b, 2b will do a recursive look-up on 1's routes and have it fail (cause the next hop is not in the forward table). So one router 2b, check for a entry and pingability of subnet between 1 and 2a. The link between router 1 and 2a is an 'infrastructure' route, so you want that in your IGP. Barry
-----Original Message----- From: owner-nanog () merit edu [mailto:owner-nanog () merit edu]On Behalf Of Tim Wolfe Sent: Tuesday, January 23, 2001 3:26 PM To: 'nanog () merit edu' Subject: Tricky BGP into IGP Question What is the preferred way to get transit customers routing information into your IGP so that BGP will announce the route to it's neighbors. 1===2a===2b====3 | 4 1 is the customer, announcing to 2a, who propogates 1's route to 2b and to 4. 2b will not announce the route to 3 as it doesn't have a route in it's routing table for 1's route. I was thinking about redistributing bgp into my igp using a route-map based on as-path filter, but that seems somewhat kludgy. What are you all doing to accomplish this or am I just missing something here? Thanks, --Tim ============================================= Timothy M. Wolfe CCNA, NSA Sr. Security Engineer tim () ignw com InfoGroup Northwest 541.485.0957 x108 =============================================
Current thread:
- Tricky BGP into IGP Question Tim Wolfe (Feb 24)
- Re: Tricky BGP into IGP Question Anne Marcel (Feb 24)
- Re: Tricky BGP into IGP Question Clayton Fiske (Feb 24)
- RE: Tricky BGP into IGP Question Barry Raveendran Greene (Feb 24)
- <Possible follow-ups>
- Re: Tricky BGP into IGP Question Danny McPherson (Feb 24)
- Re: Tricky BGP into IGP Question Paul Donner (Feb 24)
- RE: Tricky BGP into IGP Question Tim Wolfe (Feb 24)