Hi Stavros, On ven. 28 févr. 12:41:24 2020, Stavros Konstantaras wrote: > Hi Bird community, > > We are investigating a weird customer issue regarding our Bird Route > Servers (version 1.6.3) and a specific IPv6 session. Customer reports > a sudden drop of his IPv6 session and -until now- we could not relate > those drops with any issue or instability. Everything seems normal and > no other customer complained at the moment of the incident. > > > > After some packet capturing at the moment of the event, we discovered > that BIRD does not send a response messages to the customer’s BGP > keepalive messages (see attached picture), which result to the BGP > hold timer to expire and the sessions to be dropped. We observed this > anomaly with both RSs but at different time slots and the tcpdump > capture was running at the Interface were Bird is sending all BGP > traffic for customers. At the moment of the event, we didn’t do any > maintenance or other RS related work. > > Has any of you experienced this in the past? If yes, how did you solve > this? > Any related feedback is welcomed.
Do you have the MSS used to establish the session? I had an issue about a session flapping with edgecast (verizonmedia) flapping on AMS-IX because both were having a MTU at 9216 on our port. But some switch didn’t like it well and sometime a packet is loss. If it’s the one containing the keepalive, the session goes down. I resolved it by setting a MTU of 1514 on my side (which should have been since always). Also, note that I’m not directly connected to the IXP, I’m using a reseller. Regards, -- Alarig
