failed to dial: dial tcp connectex: Only one usage of each socket address (protocol/network address/port) is normally permitted.

[mr05je]

The error occurs when there are insufficient free ports on the machine.

How do I set a different ip for the session?

[Noooste]

Hello,
You can use the http.Transport inside the session, using session.Transport.
You can also assign a func(dialer *net.Dialer) error function to session.ModifyDialer to modify the dialer before the connection is established.