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.
