OSPF route costs in BIRD

I am migrating an anycast OSPF routing BIND redundant setup from Quagga to BIRD. One of my difficulties is getting several routes with different costs with BIRD, in the same way as I am doing it in quagga. As in Quagga I am doing in /etc/quagga/ospfd.conf: interface dummy0 ip ospf cost 100 ! interface dummy1 ip ospf cost 500 ! interface dummy2 ip ospf cost 1000 ! interface dummy3 ip ospf cost 900 ! I can see in birdc using the command show ospf state that my configuration is not giving weights, despite having defined the cost in the interfaces in /etc/bird.conf. What to do? protocol ospf { tick 2; rfc1583compat yes; area 0.0.0.0 { networks { 1.1.1.0/22; 2.2.2.2/32; 3.3.3.3/32; 4.4.4.4/32; 5.5.5.5/32; }; interface "eth0" { cost 1000; password "xxxxxxxxxx" { id 5; }; authentication cryptographic; }; interface "dummy0" { stub; cost 100; }; interface "dummy1" { stub; cost 500; }; interface "dummy2" { stub; cost 1000; }; interface "dummy3" { stub; cost 900; }; }; }