Short and simple question: I am new to boost::asio and I was wondering if it is possible to create a tcp::acceptor listening for both, IPv4 and IPv6 connections together. The tutorials on boost's homepage show something like this:
_acceptor = new tcp::acceptor(_ioService, tcp::endpoint(tcp::v4(), 3456));
where the endpoint is always specified with a specific protocol. Is it not possible to listen for IPv4 and IPv6 on the same port at the same time?
If you create a IPv6 acceptor, it will accept both IPv4 and IPv6 connections if IPV6_V6ONLY socket option is cleared. IPv4 addresses will be presented as IPv6 addresses, in the IPv4-mapped format.
Problems arise mainly around whether IPV6_V6ONLY is available or what the default value is (turned on or off). So I find it's better to set it explicitly to what you want.
Also Windows XP doesn't support the option at all.
So if you want to be compatible across systems, it's recommended to create two sockets, one for v4 and one for v6 setting IPV6_V6ONLY.