We have seen upon occasion where a dampened route will not be replaced by a route of the same specificity for about 20-45 minutes. While we didn't care for this behaviour, I guess it was somewhat predictable. What had us concerned was we have seen each of our three providers black hole us on at least one occasion (sometimes more) when their backbone or core flapped. It could be described as appearing as if their borders did not receive the information to withdraw our advertisements. Looking Glass showed us "history" and "received only" entries, but no active replacements... similar to the symptoms that you are describing. Sprint's NOC reported hearing active advertisements from our "down" providerm but I heard this second-hand. Killing our BGP session with the offending provider after the problem started would not fix the problem, our routes continued to be preferred to someone we no longer had a bgp session with. This situation would usually fix itself within 45 minutes. While this doesn't happen often, it has the affect that having two other providers is useless if the third is erronously advertising us. Is there a failure scenerio where borders will continue to advertise AS's due to loss of connectivity with their interior routers? Bil Herd InterActive On Thu, 5 Jun 1997, Anthony Walker wrote:

We are currently multi-homed during the day and tripple homed at night. Basicaly we (AS6180) have been announcing all our adresses including 196.25.116.0, 196.25.117.0 and 196.25.203.0 via AS 3741 at night, and this gets switched of during the day. The problem seems to relate to the fact that these addresses are part of AS 5713's CIDR 196.25.0.0/16 and we thought we could get away with announcing them like this. It did work fine for over a week, but now today we have a problem.

MAE-East (see example at end of message) , the Sprintnap and who knows who else still have entries for these via AS3741 but they are showing as received-only, and no best path. Yet via MAE West they are fine.

We are going to stop announcing these via AS3741 at night, but its been 9 hours now since they were not announced and these received-only entries are still sitting there blocking these routes from it seems about a third of the internet. MAE-East Looking Glass Results Query: bgp Addr: 196.25.203.0 BGP routing table entry for 196.25.203.0/24, version 5006458 Paths: (1 available, no best path, advertised over IBGP) 1673 1239 4005 3741 6180, (received-only) 192.41.177.141 from 192.41.177.141 (140.223.57.217) Origin IGP, external