[45056] in North American Network Operators' Group
RE: router startup behavior
daemon@ATHENA.MIT.EDU (Paul Donner)
Mon Jan 14 17:49:00 2002
Message-Id: <5.1.0.14.0.20020114154936.02bdb328@localhost>
Date: Mon, 14 Jan 2002 15:49:50 -0500
To: David Schwartz <davids@webmaster.com>, <nanog@merit.edu>
From: Paul Donner <pdonner@cisco.com>
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how long would you wait for?
At 03:32 PM 1/14/2002, David Schwartz wrote:
>On Mon, 14 Jan 2002 13:28:42 -0600, Steve Naslund wrote:
>
> >Here is my best guess as to what you are seeing. Most likely a large CIDR
> >block is announced by a service provider A. A small CIDR block is given to
> >a customer who is connected to multiple service providers and thus running
> >BGP. Now the more specific route is announced by service provider B, he
> >does not own the block but is announcing it on behalf of service provider As
> >customer. What is happening is that the customer has a line or router
> >failure and that withdraws their more specific announcement from service
> >provider B. Since the service provider A is announcing a supernet route he
> >now becomes the only route for that block.
>
> If that's the problem, a fix might be to not advertise any routes
> to a BGP
>peer until you receive all the routes that peer has to send you. I think it's
>elegant that when two routers connect, neither sends any routes to the other
>until each has received all the routes the other has to send. Very Zen, don't
>you think?
>
> DS
