To enable IPv6 on the server you need: - The Perl module Socket6 You can install it on Debian or Ubuntu with: apt-get install libsocket6-perl - Add to /etc/xinetd.d/fex the line: flags = IPv6 and remove the "bind" option line. Restart xinetd. To enable IPv6 for fexsend, fexget and sexsend you need: - The Perl module Net::INET6Glue::INET_is_INET6 You can install it on Debian or Ubuntu with: apt-get install libnet-inet6glue-perl