names=MCAST_BLOCK_SOURCE
visibility=public
kind=defined

--- MCAST_BLOCK_SOURCE -> Integer
Block multicast packets from this source

[[m:BasicSocket#getsockopt]], [[m:BasicSocket#setsockopt]]
の第2引数(optname)に使用します。

@see [[m:Socket::Constants::IPPROTO_IP]], [[m:Socket::Constants::IPPROTO_IPV6]],
     [[RFC:3678]]

