Hi, In bird i have in routing table: 10.10.96.0/22 dev vlan13 [direct1 Nov19] * (240) 10.10.96.0/19 dev vlan14 [static1 09:12] * (200) and i try to export prefix 10.10.96.0/19 to ospf protocol ospf test { import filter ospf_test_import; export filter ospf_test_export; filter ospf_test_export { if net ~ 10.10.96.0/19 then { accept; } else reject; } protocol static { import all; export all; route 10.10.96.0/19 via "vlan304"; #test#not#helped route 10.10.96.0/22 reject; } and on others ospf routers i see only: Extern 10.10.96.0 mask 255.255.252.0 There is some limit in bird or ospf or bird takes just more precise route ? I'm not sure, but for a while, when i started testing this, i saw /19 but it was a night and i was very tired.. thanks for help Peter