Hi All, I am implementing a function that send default route to BGP peer, and I am facing an issue about BGP filter, when I use "show route filter" in birdc, the filter result is correct; when I add this filter to config-file and start bird, the bird will occur coredump issue. Does anyone know the reason? Appreciated in advance. 1. bird>show route filter {if format(net) = "0.0.0.0/0" then accept;} //correct result /* show route filter {if net = "0.0.0.0/0" then accept;} // incorrect result */ 2. config-file: filter filter_bgp1{ if format(net) = "0.0.0.0/0" then accept; // "format(net) = ..." , bird coredump ??? /* if net = "0.0.0.0/0" then accept; // " net= ..." , not bird coredump*/ } protocol bgp bgp1 { ...... ipv4 { import all; export filter filter_bgp1; }; ........ } Thanks Arvin