Multicast and security

[Olivier Nicole]

> I'm looking at adding MROUTING to my gateway/firewall box (Soekris
> 4801 running 5.4 RC2).  However having not played with multicast
> before I'm looking for pointers on the security issues (I don't want
> to create a gaping hole in my FW).

It depends on how your ISP is doing his multicast routing. Here we are
using PIM and it means:

PIM proto 103 from router to router and from router to 224.0.0.13/32

IGMP proto 2 from client to 224/4

UDP from client to 224/4

Olivier