IPV6_MULTICAST_LOOP  550 net/udp/udp_socket_libevent.cc       rv = setsockopt(socket_, IPPROTO_IPV6, IPV6_MULTICAST_LOOP,
IPV6_MULTICAST_LOOP  644 net/udp/udp_socket_win.cc         addr_family_ == AF_INET ? IP_MULTICAST_LOOP: IPV6_MULTICAST_LOOP;