I have secured a linux box, starting with

iptables -P INPUT DROP
iptables -P OUTPUT DROP
iptables -P FORWARD DROP

and after adding rules to enable specific protocols and streams.

• Which are the correct rules to add multicast support ?

I am trying with these - for both client and server multicast :

iptables -A INPUT  -m pkttype --pkt-type multicast -j ACCEPT
iptables -A OUTPUT -m pkttype --pkt-type multicast -j ACCEPT
iptables -A INPUT  --protocol igmp -j ACCEPT
iptables -A OUTPUT --protocol igmp -j ACCEPT
iptables -A INPUT  --dst "224.0.0.0/4" -j ACCEPT
iptables -A OUTPUT --dst "224.0.0.0/4" -j ACCEPT

Linux 2.6.38-12 / iptables 1.4.10

• Is there any internet service to test my multicast set ( pc + adsl router + provider ) ?