Hi. > 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.
In this case better use OSPF+BFD solution - it's much more stable + you can get less-second failover. On Tue, Nov 4, 2014 at 2:52 AM, Alex Laties <[email protected]> wrote: > 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." > >
