Is there a way to increase the 20 multicast group limit per socket?

Question

As the title says, is there a way to increase the limit of 20 multicast groups that you can join on a given socket? Is there some system setting that I am missing or is there some hard limit which cannot be exceeded?

Answer 1

Well, incase someone is searching for this, the following parameter exists:

/proc/sys/net/ipv4/igmp_max_memberships

Currently my install says 20, in the sources, I also see:

bits/in.h:#define IP_MAX_MEMBERSHIPS              20

I think bumping up the system parameter may be enough, else will have to patch the header as well!

EDIT: looks like bumping up the system parameter does the trick.