Server:
nc -l -u 64739
<type letters, client doesn't see them>

Client:
nc -u intranet 64739
<type letters, press ENTER>
nc: Write error: Connection refused

Server:
nc -l 64739
abc

Client:
nc intranet 64739
abc

(both ways works through TCP)

My ip6tables config is allowing all traffic through eth1 (-A INPUT -i eth1 -j ACCEPT). eth1 being the network card that is on the server that is physically connected to the same network as the client. All IPv6 TCP traffic is working great. SSH, HTTP, etc.

What am I missing?

Thanks,
Michael