Not on all OSes. And it's not all good to have one less socket, there are still issues with people not expecting v4 traffic on a v6-capable socket, like describ

Not on all OSes. And it's not all good to have one less socket, there are still issues with people not expecting v4 traffic on a v6-capable socket, like described here: https://radar.offseq.com/threat/ipv4-mapped-ipv6-addresses-tue-mar-17th-d7adc16f https://radar.offseq.com/threat/ipv4-mapped-ipv6-addresses-t... If you want to handle two protocols, it is not unreasonable to use two sockets.