RHEL: setsockopt() for adding multicast member returns -ENOBUFS

Issue

This ticket is related to our Openstack infrastructure but we have reproduced the error on a basic Redhat Linux Server. Each time a network (vlxan) is created in our Openstack infrastructure, a multicast address is joined to manage broadcast requests.

We noticed recently that DHCP was not working for any new networks while it continued to work for older networks. We also noticed that ARP requests didn't work while a simple ping worked (actually, the problem is only for broadcast requests)
After a lot of investigations, we found the source of the problem. Some multicast groups were not joined because of this error:

mcast-daemon[1562]: [src/MulticastListener.cpp:101:join] Could not join group 226.0.1.1: No buffer space available