I'm new to firewall configuration and I've been reading some theory and studying example configurations. One thing that I noticed is that many of those examples allow IGMP packets.
The Wikipedia article is a bit vague on that:
IGMP is vulnerable to some attacks,[2][3][4][5] and firewalls commonly allow the user to disable it if not needed.
Should I allow IGMP traffic if I don't have any deployed software that explicitly insists on it being allowed? As far as I understand, blocking ICMP is a terrible idea and it harms network performance, but what about IGMP? Do home routers rely on it for stable day-to-day operations? What about virtual private servers in data centers?
