7.12. If All Else Fails...

In some cases you may use software that simply does not support IPv6. In some cases this software can be made to effectively operate over IPv6 using port forwarding. We use the nc6 program, available from http://www.deepspace6.net/projects/netcat6.html, and inetd to do port forwarding. The nc6 program allows you to make a connection to a network service and copies its input/output to that network service. For example, you could say nc6 mail.example.com smtp to get a connection to the SMTP server on mail.example.com.

There are other more sophisticated solutions using programs, such as ssh. Examples of clever port forwarding tricks can be found in SSH, The Secure Shell by Barrett and Silverman (O'Reilly). These tricks work over IPv4, IPv6, and a mix of both.