Indeed minissdpd does bind() the socket on *:1900 but adds membership
(join group for IPv6) to the multicast group 126.96.36.199(FF02::C,
FF05::C) only on the specified interface(s).
Then, the first thing done when a packet is received is to check the
interface and or the peer address :
Non matching packets are dropped.
Binding on a specific address may or may not work properly depending on
the way the OS implements IP Multicast.
it can be enabled at compile time but was disabled for incompatibilities