[Nottingham] DLNA across subnets?

[Jason Irwin]

It's me and networking again - so you may wish to simply look away now!

I've got 'home' and 'untrusted' LANs on different subnets.
Our new, so smart it's annoying, TV is on the 'untrusted' network and I
have a DLNA server on 'home'.
Despite me dropping the firewall between the two networks, the TV and
server can't see each other.
If I move the server onto 'untrusted' it's all tickety-boo. So I am sure
it's not some TV/server incompatibility. I've also tested the server
against Andorid and Kodi, all OK so long as they are on the same subnet.
Pint etc between the two subnets seems to be fine.

I suspect this is some kind of multicast issue and I've been all over the
web GUI of the router looking for any "multicast" setting and bar "Filter
multicast" on the firewall (disabling it had no effect), I couldn't find a
thing.

Is there some fundamental issue with multicasting between subnets, or can I
inject some magic into iptables to resolve it?

So far my searching has found me lots of unanswered forum posts but no
answer.

It's a Buffallo WZR-HP-AG300H router running a Buffalo-branded DD-WRT v24
SP2.

Cheers,

J.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.lug.org.uk/pipermail/nottingham/attachments/20150111/897e8dff/attachment.html>