Hi,
I agree with you, it should not be the case here.
But, we are running over mobile networks, and the openvpn adds some overhead.
Running some tcpdump shows that the packet lenght of the hello packet is just about 480, and that should be ok.
If we change to another openvpn instance/interface and change over to that it works directly.
I have also updated bird on our mainrouter to 1.6.3 (latest), but the issue still exist.
I have attached our config files (bird.conf (mainrouter), bird_client.conf (from one of the end router)).
My OSPF knowlege are limited, so I guess that I have made some errors :)
The main feature we need is to distribute some external routes (10.3.50.0/24, 10.3.60.0/24), and distribute back the endpoints IP networks (10.98.x.x/30)
/ Magnus