Hi, I am using BFD neighbor to config BFD sessions statically. I found that if I add/remove BFD neighbors in bird.conf  and ask bird to reload with HUP signal, bird cannot reload the configuration correctly. Here is the BFD config I used to test. If I start bird with this configuration, then comment one of the neighbors and send HUP with kill to bird, bird simply says session reconfigured without remove the commented neighbor. protocol bfd { interface "*" {         passive; }; neighbor 172.17.0.2; neighbor 172.17.0.3; } After digging into the code, I found that it looks like there is a bug in function bfd_reconfigure_neighbors. It loops to check neighbor in old and new configuration. There is a return in the block if (bfd_same_neighbor(nn, on)). If there is  neighbor existing in both new and old, reconfiguration might be skipped. I tried to modify the code to make it work. And the attached patch is the one I got. Hopefully this is the proper way to solve the issue. Regards. Chen.