I’ve put together an initial attempt at IPv6 support in swaks. If this sort of thing interests you, please take a look at what I have so far and let me know what you think.
LINK REMOVED – this was a development release and the changes have been incorporated in official releases. Please see the project home page at http://jetmore.org/john/code/swaks/ for the latest release.
There is no documentation included yet, but the only real change to the documentation is the addition of the -4 and -6 options to force IPv4 or IPv6. There are a few unrelated tweaks since the last release, but nothing that needs documentation at this point.