You're right, a transient sub-50 msec hit should not be enough to interrupt a BGP session, but we believe that in this occurrence of the SONET protection mechanism had some kind of negative effect. They do protection switches more often (road construction, etc), I'm told, and we've never had an issue. My guess is that the protection switch affected the Ethernet port on their transport equipment feeding their PE Ethernet switch which feeds our router (so there is a "buffer" between their equipment and ours. What's interesting is that the "fix" was to bounce the Ethernet port on the router facing us. They told us that they did not touch anything else on their transport equipment.
They opened up a case with Cisco TAC, but because our upstream provider resolved the issue Cisco didn't have an opportunity to do any deep diagnoses. I'm open to any other creative speculation. Frank -----Original Message----- From: Robert Blayzor [mailto:[EMAIL PROTECTED] Sent: Thursday, April 10, 2008 7:24 PM To: [EMAIL PROTECTED] Cc: [email protected] Subject: Re: [c-nsp] Identifying BGP route flapping On Apr 10, 2008, at 4:24 PM, Frank Bulk wrote: > Yes, there was an event that caused the router flapping to happen, > but it > was clearly an anomaly. There was a sub-50 msec interruption in > Ethernet > traffic on the upstream for one router that caused the two routers > (connected with each other over a separate link) to go haywire. Would a transient sub-50msec hit actually be enough to interrupt a BGP session? Or is the physical interface flapping state and causing the peer to reset? -- Robert Blayzor, BOFH INOC, LLC [EMAIL PROTECTED] http://www.inoc.net/~rblayzor/ Mac OS X. Because making Unix user-friendly is easier than debugging Windows. _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
