Hey Ondrej, So, we've had debug enabled from the start of our deployment. We currently have "debug protocols all" set.
>From what I can glean from the logs, these messages appear after some time after the adjacency has been established. Our current deployment has juniper routing instances talking OSPF, as well as linux boxes talking OSPF via bird. The OSPF interface is in broadcast mode I believe. In terms of unusual settings, we have some rather aggressive OSPF hello and dead timers set. Hellos are set to 1 a second, and dead set to 3 seconds. What we tend to see in our logs from bird is that occasionally, bird fails to send a Hello packet for 2 or 3 seconds. More specifically, we see gaps of 2 to 3 seconds in the log file. We've disabled debug on one of our active nodes. The frequency for that node to go from Full to Down is significantly lower than it's peers at the moment (once a day vs once or twice every couple of hours). We're testing bird 1.4.5 on one of our nodes for the next 48 hours and will report back with results there. On Mon, Nov 3, 2014 at 5:35 AM, Ondrej Zajicek <[email protected]> wrote: > On Mon, Oct 27, 2014 at 09:42:32PM -0400, Alex Laties wrote: > > Hi all, > > > > We currently have a large production deployment using version bird 1.3.7 > > for OSPF. > > > > We're seeing the following message pretty frequently in our logs: > > > > > dbdes - sequence mismatch neighbor 192.168.39.216 (full) > > > > The period between these messages is irregular. Sometimes these occur > > within a few seconds of each other. Sometimes it can be a few hours > between > > these messages. > > Hi > > These messages are the result of receiving DBDES packets when a neighbor > adjacency is already established. This shouldn't happen in normal > operation, although i would guess it might happen in some circumstances > if the other side is hard restarted and became available again before the > other side notices it (by inactivity timer). > > > First, i would suggest to use latest version of BIRD. > > Second, i would suggest enabling 'debug { events }' for OSPF protocol > to see what happens on boths sides immediately before the mismatch. > > Are these messages appear just after the neighbor changed state to full > or after some time after the adjacency establishment? > > Is the other side also BIRD? > > Is the OSPF interface in broadcast or ptp mode? > > Is this regular or some kind of unusual setting? > > > -- > Elen sila lumenn' omentielvo > > Ondrej 'Santiago' Zajicek (email: [email protected]) > OpenPGP encrypted e-mails preferred (KeyID 0x11DEADC3, wwwkeys.pgp.net) > "To err is human -- to blame it on a computer is even more so." >
