[Python-Dev] socket.create_connection slow

["Martin v. Löwis"]

> And Microsoft, realizing their problem , came up with this:
> http://msdn.microsoft.com/en-us/library/bb513665(VS.85).aspx

Dual-stacked sockets are a useful thing to have (so useful that
Linux made them the default, despite that the RFC says that the
default should be IPV6_V6ONLY). The Python library should make
all server sockets dual-stacked if possible.

Unfortunately:
- the socket option is not available on all systems, in particular,
  it is not available on Windows XP (you need Vista)
- you'll see the 1s delay on the client side if the server is
  not dual-stacked, so if the server "misbehaves", the client has
  to suffer.

Regards,
Martin