[I dropped tech-net@netbsd.org since this thread doesn't belong on that
list.]

I use quagga.  Recent quagga seems to have a regression on sparc64 for
ipv6 at least (I only run v6 bgp), but 0.99.4 works fine.

You probably should check out openbgpd.  I am not clear how that
interacts with an IGP; quagga has a master daemon that interacts with
the kernel and allows route redistribution (typically static -> ospf,
less so to/from bgp).