Those are both good questions. I didn't catch it when it occurred but I will remove traffic from the PE router and then simulate the failure.
Thanks, -Drew -----Original Message----- From: cisco-nsp <[email protected]> On Behalf Of [email protected] Sent: Thursday, October 8, 2020 12:27 PM To: '[email protected]' <[email protected]> Subject: Re: [c-nsp] Sanity check OSPF/BGP On Thursday, 8 October, 2020 17:08, "Drew Weaver" <[email protected]> said: > Previously, when we had this issue it was determined that it was > because there was still a route to the BGP neighbor in the routing > table (because the neighbor IP was part of our IP announcements and it > would wait until the hold time to expire) but we got around that > particular issue by using RFC1918 IPs for the neighbors and BGP Next > hop address tracking took care of the rest (made it much faster, like > 1-2 > seconds) but it seems like in our current architecture with the new > core it’s operating differently. > > It’s almost like the new core routers are continuing to be seen as a > path to this neighbor by the old core routers and vice versa even > though OSPF went down on both of them at the same exact time. > > It’s a mystery for sure. Back to basics - what does "show ip route <remote-loopback>" give you during that two-minute window? Is there a default route somewhere in the network that could be flagging that remote loopback as still reachable until the BGP timers expire? Regards, Tim. _______________________________________________ cisco-nsp mailing list [email protected] https://urldefense.proofpoint.com/v2/url?u=https-3A__puck.nether.net_mailman_listinfo_cisco-2Dnsp&d=DwIGaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=OPufM5oSy-PFpzfoijO_w76wskMALE1o4LtA3tMGmuw&m=_cSub4IuCJHW5XB79UH_LPiDCfSxIPffvNUrwnxvRvY&s=Kl9GNS56uGL5HQZUmIUfahKk_TD4gtJS5tDOWHYouq4&e= archive at https://urldefense.proofpoint.com/v2/url?u=http-3A__puck.nether.net_pipermail_cisco-2Dnsp_&d=DwIGaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=OPufM5oSy-PFpzfoijO_w76wskMALE1o4LtA3tMGmuw&m=_cSub4IuCJHW5XB79UH_LPiDCfSxIPffvNUrwnxvRvY&s=015GrnASWjArHeY-MuBADAzBLm9LzWlzvETEmquqtcw&e= _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
