Hello, BIRD developers! Currently there is no way in filter rules to match routes by interface name and interface index. However string comparison (=,!=,>,<,... operations), and pattern matching (using ~ operator) already implemented in filters, so expressions like: if "eth0" ~ "eth*" || "eth1" = "eth1" then print "This pattern matches!"; already works. Only one thing that is really needed is exposing attribute with name to filter which references route outgoing interface name and index. Of course all of these variables must be readonly. Interface indexes are taken from kernel (at least on Linux, and FreeBSD) and represents interface number in system. Matching to indexes is not such reliable as matching with interface names, as indexes might change on interface addition/removal. Currently only sink (blackhole, unreachable and prohibit) routes in BIRD have no interface associated. Return an empty string and index equal to zero (no real index in kernel) for such routes. -- SP5474-RIPE Sergey Popovich