ipv6 / rtadv problem

[Bernd Walter]

On Tue, Mar 29, 2011 at 11:43:57PM +1030, Daniel O'Connor wrote:
> 
> It is running a fairly old FreeBSD (6.x..), maybe there are bugs there..

I don't think there are general bugs about neighbor discovery in FreeBSD
since the beginning, but NIC drivers might have multicast bugs and
although you are running this host since a long time such bugs might be
unnoticed.
You can show and clear the neighbor cache data by using ndp command,
which has similar handling as arp.
If you use tcpdump to debug NDP packets be aware that by enabling
promiscuous mode you get every multicast packet despite of correct
filter setup, so you won't see a problem if the driver isn't
configuring the filter correctly.
On the other hand you can workaround a such driver bug by enabling
promiscuous mode.

-- 
B.Walter <bernd at bwct.de> http://www.bwct.de
Modbus/TCP Ethernet I/O Baugruppen, ARM basierte FreeBSD Rechner uvm.