nanog mailing list archives

Re: bgp feed to customer


From: Iljitsch van Beijnum <iljitsch () muada com>
Date: Mon, 13 Jun 2011 19:36:50 +0200

On 13 jun 2011, at 19:25, Richard Zheng wrote:

The issue is redistribution from EBGP to OSPF works half way. OSPF database
has the external routes, but forwarding address is set to Router A. So the
routing loop occurs between A and B.

If the link to the customer is of a type that detects up/down quickly, the easiest way to get around this is to simply 
point a default to the customer interface at router B.

Another option is running a separate OSPF instance between B and the customer.

Or just ignore the issue that if/when the link to the customer goes down, router B doesn't notice and keeps forwarding 
packets into the void. You would want to make sure that the customer's prefix isn't propagated in OSPF, though, so the 
issue is limited to this one router, not the whole AS.

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