On Sat, Mar 15, 2025 at 11:07:04AM +0000, Lexi Winter via Bird-users wrote: > hello, > > recently i noticed some entries in syslog like this: > > Mar 15 11:03:22 uk-myb-2 bird[60388]: nl-myb-1: Invalid NEXT_HOP attribute - > neighbor address fd5b:a83:b06b:500::1 > Mar 15 11:03:22 uk-myb-2 bird[60388]: nl-myb-1: Invalid route 172.20.212.0/26 > withdrawn > Mar 15 11:03:22 uk-myb-2 bird[60388]: nl-myb-1: Invalid NEXT_HOP attribute - > neighbor address fd5b:a83:b06b:500::1 > Mar 15 11:03:22 uk-myb-2 bird[60388]: nl-myb-1: Invalid route 172.20.212.0/26 > withdrawn > Mar 15 11:03:22 uk-myb-2 bird[60388]: nl-myb-1: Invalid NEXT_HOP attribute - > neighbor address fd5b:a83:b06b:500::1 > Mar 15 11:03:22 uk-myb-2 bird[60388]: nl-myb-1: Invalid route 172.20.212.0/26 > withdrawn > Mar 15 11:03:22 uk-myb-2 bird[60388]: nl-myb-1: Invalid NEXT_HOP attribute - > neighbor address fd5b:a83:b06b:500::1 > Mar 15 11:03:22 uk-myb-2 bird[60388]: nl-myb-1: Invalid route 172.20.212.0/26 > withdrawn > > i am not sure how to understand this log message. > > what is BIRD trying to indicate with this log message?
Hello The message is generated during route export and means that the NEXT_HOP attribute for the route that would be announced to the neighbor is the same as the IP address of that neighbor. This is not valid, so BIRD sends a route withdraw instead of an update. Because it is an error during route export, the local situation is fine, but the route is not announced to the neighbor. > i still have the route (including via nl-myb-1): > > root@uk-myb-2:~ # birdc show route 172.20.212.0/26 > BIRD 2.16.1 ready. > Table master4: > 172.20.212.0/26 unicast [uk-jmp-2 11:03:22.032 from > fd5b:a83:b06b:400::1] * (100/61) [AS4242422622i] > via fe80::e0e3:b1bf:8d1d:abcd on wg.nl-myb-1 > unicast [nl-myb-1 11:03:20.704 from > fd5b:a83:b06b:500::1] (100/61) [AS4242422622i] > via fe80::e0e3:b1bf:8d1d:abcd on wg.nl-myb-1 > unicast [ny-czy-1 11:03:20.589 from > fd5b:a83:b06b:200::1] (100/694) [AS4242422622i] > via fe80::bc1b:dbed:690a:6840 on wg.uk-jmp-2 > unicast [mia-czy-1 11:03:20.680 from > fd5b:a83:b06b:900::1] (100/694) [AS4242422622i] > via fe80::bc1b:dbed:690a:6840 on wg.uk-jmp-2 > > and it's in the FIB as well: > > root@uk-myb-2:~ # route -n get -inet 172.20.212.0/26 > route to: 172.20.212.0 > destination: 172.20.212.0 > mask: 255.255.255.192 > gateway: fe80::e0e3:b1bf:8d1d:abcd%wg.nl-myb-1 > fib: 0 > interface: wg.nl-myb-1 > flags: <UP,GATEWAY,DONE> > recvpipe sendpipe ssthresh rtt,msec mtu weight expire > 0 0 0 0 1420 1 0 > > so everything seems fine. -- Elen sila lumenn' omentielvo Ondrej 'Santiago' Zajicek (email: santi...@crfreenet.org) "To err is human -- to blame it on a computer is even more so."
