Hi all. I'm trying to set up a VPN between two locations, with routing (not bridging) between the two networks (so I'm using openvpn on tun0, not tap0). Then I'd like to get mDNS forwarding across the VPN. This gives me a happy medium between routed and bridged subnets.
I had this working before under kamikaze, and liked the resulting behavior. I've upgraded everything to backfire, and am trying to get back to the same point.
At this point I've installed and configured openvpn, installed avahi-daemon, but I'm not seeing any mDNS traffic across the VPN link.
I know that I need to add "allow-point-to-point=yes" to the [server] section of /etc/avahi/avahi-daemon.conf; I've done that. And I've enabled avahi's reflector with "enable-reflector=yes".
If I start avahi-daemon from the command line as "avahi-daemon --debug" so I can see its debug output on the console, I see it start up and "joining mDNS multicast group" for the br-lan, eth1 and tun0 interfaces, as I'd expect. (Without allow-point-to-point, it ignores tun0.)
However, if at this point I watch mDNS traffic on the VPN link with "tcpdump -i tun0 udp port 5353", and do mDNS lookups from another machine on my LAN, tcpdump sees no traffic.
If I do "tcpdump -i br-lan udp port 5353" on the router and do mDNS lookups from another machine, tcpdump sees the requests (on the lan, regardless of whether avahi-daemon is running or how it's configured).
If I do "tcpdump -i eth1 udp port 5353" on the router and do mDNS lookups from another machine, tcpdump sees the requests (only if avahi-daemon is running and the reflector is enabled and I haven't denied it from using eth1); this proves that avahi's reflector is active, and both necessary and sufficient for 5353 traffic on eth1.
However, nothing I've tried has resulted in any udp port 5353 traffic whatsoever on the vpn link.
I have a hunch, possibly wildly incorrect, that avahi doesn't like something about the tun0 interface, which ifconfig shows as
root@wormhole:/etc/avahi# ifconfig tun0 tun0 Link encap:UNSPEC HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00
I don't remember the link having empty encap and hwaddr under kamikaze, though I could be misremembering.
Anyway. Anyone have this working, know what's wrong or what to change? Thanks in advance.