OSPF on bridged network

[Dean]

Hello,

I'm trying to setup OSPF to run between docker containers, and I have 
connected three containers to a bridge using veth interfaces.
However, each container considers itself to be Designated Router for the 
network, and doesn't even acknowledge the others (none is in the 
neighbor list). Below is my configuration:

log "/bird/rt3/bird.log" all;

router id 3;

protocol device {
     scan time 10;
}

protocol kernel {
     export all;
     scan time 15;
}

protocol ospf {
     debug all;
     import all;

     area 1 {
         networks {
             2001:db9:4::/64;
         };

         interface "v4" {
             cost 5;
             type ptp;
             hello 5; retransmit 2; wait 10; dead 20;
         };

         interface "vn3" {
             priority 3;
             cost 5;
             type broadcast;
             hello 5; retransmit 2; wait 10; dead 20;
         };
     };
}

The two other containers have the pretty much the same configuration. 
Only the interface names, priority and router ID is different.
Any idea what is going on here?

Thank you.