Not receiving OSPF Hello even though tcpdump shows it's received

[Victor Bolaños Guerra]

Hi,

Can you send your RouterOS version and /routing export?

Best regards,

El jue, 15 ene 2026 a las 5:43, Lukas Haase via Bird-users (<
bird-users at network.cz>) escribió:

> Hi,
>
> I have been running OSPF between Bird and Mikrotik RouterOS over wireguard
> tunnels for over two years, no issue.
>
> I have not changed ANYTHING (to the best of my knowledge) but this morning
> I randomly notice some connectivity issues. I started to debug this evening
> and found that all OSPF neighbors have been in "ExStart" on RouterOS for 15
> hours or so. I tried to debug back and forth and eventually I rebooted all
> systems. Now all Mikrotik neighbors are stuck in "Init" and for my life of
> it I can't figure out why. IT WORKED FOR TWO YEARS!!! I neither changed
> Mikrotik side nor Bird side!
>
> Anyway, I started debugging from scratch and I noticed one thing: Both
> bird and RouterOS send OSPF Hello's:
>
>
> # tcpdump -i wg-b -n 'proto ospf'
> tcpdump: verbose output suppressed, use -v[v]... for full protocol decode
> listening on wg-b, link-type RAW (Raw IP), snapshot length 262144 bytes
> 05:32:39.013170 IP 1.2.3.210 > 224.0.0.5: OSPFv2, Hello, length 48
> 05:32:39.895227 IP 1.2.3.185 > 224.0.0.5: OSPFv2, Hello, length 44
>
> I enabled OSPF debugging and only see this:
>
> Jan 15 05:32:24 BorderGate1 bird[35754]: ospf1: HELLO packet sent via wg-a
> Jan 15 05:32:24 BorderGate1 bird[35754]: ospf1: HELLO packet sent via wg-b
> Jan 15 05:32:24 BorderGate1 bird[35754]: ospf1: HELLO packet sent via wg-c
> Jan 15 05:32:24 BorderGate1 bird[35754]: ospf1: HELLO packet sent via wg-d
> Jan 15 05:32:27 BorderGate1 bird[35754]: ospf1: HELLO packet received from
> nbr 194.182.221.80 on wg-c
> Jan 15 05:32:28 BorderGate1 bird[35754]: ospf1: HELLO packet received from
> nbr 1.2.3.195 on wg-d
>
>
> So bird is sending an OSPF Hello on all interfaces but is receiving none
> on wg-b. However, tcpdump clearly shows wg-b receives a Hello!
>
> How the heck can this happen?
>
>
> Thanks!
>
>


-- 

Víctor Bolaños

Training Manager & Consultant

+34 911 88 03 66

+34 605 75 90 75
<https://www.linkedin.com/in/victorbguerra/>
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