pub fn probe_bind(ip: Ipv4Addr) -> Result<(), BindFailure>Expand description
Replay mdns-sd’s new_socket_bind for the IPv4 interface ip: a UDP socket
with address reuse, bound to 0.0.0.0:5353, joined to the mDNS group on ip,
with ip as the multicast interface, then one empty packet to the group.
Ok means every step worked, so a failure to announce was not a bind failure.