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- neighbor address fd5b:a83:b06b:500::1 Mar 15 11:03:22 uk-myb-2 bird[60388]: nl-myb-1: Invalid route 172.20.212.0/26 withdrawn Mar 15 11:03:22 uk-myb-2 bird[60388]: nl-myb-1: Invalid NEXT_HOP attribute - neighbor address fd5b:a83:b06b:500::1 Mar 15 11:03:22 uk-myb-2 bird[60388]: nl-myb-1: Invalid route 172.20.212.0/26 withdrawn Mar 15 11:03:22 uk-myb-2 bird[60388]: nl-myb-1: Invalid NEXT_HOP attribute - neighbor address fd5b:a83:b06b:500::1 Mar 15 11:03:22 uk-myb-2 bird[60388]: nl-myb-1: Invalid route 172.20.212.0/26 withdrawn Mar 15 11:03:22 uk-myb-2 bird[60388]: nl-myb-1: Invalid NEXT_HOP attribute - neighbor address fd5b:a83:b06b:500::1 Mar 15 11:03:22 uk-myb-2 bird[60388]: nl-myb-1: Invalid route 172.20.212.0/26 withdrawn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: santiago@crfreenet.org) "To err is human -- to blame it on a computer is even more so."