I have run into this issue before when using MD5 authentication on BGP Neighbors between Cisco and Juniper devices. I believe that issue(long time ago) was related to the fact that the MSS that was negotiated was not taking into account the 20 bytes for the MD5.
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Keegan Holley Sent: Wednesday, June 22, 2011 10:29 AM To: Abhi Cc: juniper-nsp Subject: Re: [j-nsp] BGP MTU Mismatch :) I found the MTU issue and fixed it because it was an obvious error. I don't see anything saying that BGP should care about MTU sizes though. I'm just curious to see if anyone else ran into this type of behavior and figured out the root cause. 2011/6/22 Abhi <[email protected]> > Hi Keegan > > how did u solve the problem of bgp flap in first place. > > Regards > Abhijeet.C > > > ----- Original Message ----- > From: Keegan Holley <[email protected]> > To: juniper-nsp <[email protected]> > Cc: > Sent: Wednesday, June 22, 2011 2:08 PM > Subject: [j-nsp] BGP MTU Mismatch > > Does anyone know why a BGP session would constantly flap because of an MTU > mismatch. I'm sure it's MTU since that is what fixed the problem. The > peering is between a cisco and a juniper and both support PMTU discovery. > I > would assume any mismatches would be settled by the TCP MSS negotiation or > fragmentation (admittedly bad). The peering flapped almost every three > minutes on the mark so it never made it past the first dead timer interval. > Just curious if someone out there had ever gotten to the bottom of this > problem. > _______________________________________________ > juniper-nsp mailing list [email protected] > https://puck.nether.net/mailman/listinfo/juniper-nsp > _______________________________________________ juniper-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/juniper-nsp _______________________________________________ juniper-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/juniper-nsp

