i haven't traced this problem all the way to the root cause, but here goes...
Problem: I have compiled tux2.4.5B6 and it breaks my bonded configuration (2 NICs, 1 IP).
I can ping my server's loopback interface.
i.e. "ping localhost" works locally.
but I CAN'T locally ping myself using my hostname.
i.e. "ping servername" doesn't work locally.
I can ping my server from other hosts.
i.e. "ping servername" works from other machines.
I can't ypbind to my ypserv process. it times out.
I have compiled a non-Tux 2.4.5 kernel, a non-Tux 2.4.5-ac4 kernel, and a non-Tux 2.4.5-ac9 kernel. They all work. So it is definitely Tux and not 2.4.5 or the AC patches.