router startup behavior

Paul Donner pdonner at
Mon Jan 14 20:49:50 UTC 2002

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

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