[squid-users] FTP access for IPv6 clients

Hello,

I'm using Squid as a http/ftp proxy on a university, most of your
workstations and servers have IPv6 activated.

I recently upgraded my Squid proxies to version 3.1.6 (Debian Squeeze)
and the workstations are connecting to the proxy using IPv6 (or IPv4)
with no problem.

A few computers need to access FTP servers on the Internet and there are
some issues when accessing a IPv4 FTP server : the FTP client
(FileZilla) is using IPv6 to connect to the proxy and it uses FTP
commands unknown to the FTP server (EPSV for example), using the
"ftp_epsv off" option in Squid has no effect.

As a workaround, to force FTP clients to connect to Squid using IPv4, I
created a "proxy-ftp" entry in our DNS pointing to the IPv4 address of
the proxy. If FileZilla is configured to use "proxy-ftp", it's working fine.

The problem is that sometimes the FTP server has IPv6 enabled and then
it's not working, the workstation is using IPv4 to reach Squid which is
using IPv6 to reach the FTP server. The FTP client is immediately
failing after a PASV command.

Is there a known solution to my issue? I did not make network capture yet.

Regards,

Nicolas
Received on Wed Jun 06 2012 - 20:28:34 MDT