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View Full Version : Multicast and Rendezvous discovery and a firewall



Simon Tennant
2004-05-12, 08:17
I currently run the slimp3 server on my linux box.

I understand that the server is supposed to be broadcasting a
Rendezvous discovery name and that this should show up in iTunes so
long as I'm on the same subnet.

Can anyone let me know what firewall options I should have to allow
this. At the moment I have:

# multicast
iptables -A INPUT -i eth1 -s 224.0.0.0/4 -j accept-log
iptables -A INPUT -i eth1 -d 224.0.0.0/4 -j accept-log
iptables -A OUTPUT -o eth1 -s 224.0.0.0/4 -j accept-log
iptables -A OUTPUT -o eth1 -d 224.0.0.0/4 -j accept-log

This should allow everything multicast in and out of the sever to my
client on the same subnet.

But I cannot see the Slimp3 server showing up as a service in iTunes.
Should it?

S.

_Simon Tennant

Phil Barrett
2004-05-12, 09:08
On 12 May 2004, at 16:17, Simon Tennant wrote:
> I currently run the slimp3 server on my linux box.
>
> I understand that the server is supposed to be broadcasting a
> Rendezvous discovery name and that this should show up in iTunes so
> long as I'm on the same subnet.
>
> Can anyone let me know what firewall options I should have to allow
> this. At the moment I have:
>
> # multicast
> iptables -A INPUT -i eth1 -s 224.0.0.0/4 -j accept-log
> iptables -A INPUT -i eth1 -d 224.0.0.0/4 -j accept-log
> iptables -A OUTPUT -o eth1 -s 224.0.0.0/4 -j accept-log
> iptables -A OUTPUT -o eth1 -d 224.0.0.0/4 -j accept-log
>
> This should allow everything multicast in and out of the sever to my
> client on the same subnet.
>
> But I cannot see the Slimp3 server showing up as a service in iTunes.
> Should it?

The server doesn't broadcast (except at startup and shutdown); it
listens for mDNS (LLMNR) queries from iTunes on multicast UDP port 5353
and replies to them. I guess the reply will be sent directly to the
iTunes PC/Mac from the server, which is why it's being blocked.

NB 224.0.0.0/4 are illegal as source addresses, so irrelevant in the
iptables setup above.

Phil