I have a system with a restrictive firewall that will be participating in UDP multicasting (sending and receiving). What's a good set of rules to make the host's firewall allow this?
This is my current setup, using ipf on Solaris:
# Enable UDP multicasting
pass out log quick on INTERFACE proto udp from HOSTIP/32 to 224.0.0.0/4
pass in log quick on INTERFACE proto udp from 224.0.0.0/4 to HOSTIP/32
# Enable multicast ping discovery
pass in log quick on INTERFACE proto icmp from any to 224.0.0.1/32
# Allow pings out.
pass out quick on INTERFACE proto icmp all keep state
The host is expected to participate in exactly one multicast group. Can I replace "224.0.0.0/4" with this specific group (e.g., GROUP/32) without causing problems?
Are there any other openings that should be created?