i do work since a little time in a new IPv6-only local network and there
is a SOCKS5-Proxy for accessing the public/global Internet.
The SOCKS-Proxy is configured through a PAC-Script what can found by the
"Web Proxy Autodiscovery Protocol" (
PAC-Script is correctly found and read by Firefox (configured for
autodetection the internet connection), even its HTTP-Server is also
IPv6-only in the local network.
If i try a local server name then the PAC-Script returns "DIRECT" and
Firefox do a local DNS-Query (that result is an AAAA-Record) and
afterwards Firefox connect properly to the local server.
If i try a public server from the internet then the PAC-Script returns
"SOCKS5 [Proxy-IPv6-Address]:Port" and Firefox do nothing, i can not see
any TCP-Connection to the SOCKS5-Proxy with wireshark. When i set the
"socks_remote_dns" to 'false' i see a DNS-Query to the local DNS-Server
and its negative response but Firefox do also nothing to connect to the
The only way for accessing the Internet with Firefox is to setup a local
Proxy that is accessible by IPv4 (like "ssh -D 127.0.0.1:1234
configure it directly in the Firefox-GUI. This way disables the Features
of the PAC-Script also.
All other Browsers, that i have tested, Chromium / Safari / Internet
Explorer, are working correctly with configuration set to "autodetection
the internet connection". As far as is see this Problem is present in
_all_ Firefox versions on _all_ Platforms.
In my Opinion this is a major Bug in Firefox. In Bugzilla are multiple
Bugs present for this Problem, but non of them are solved.
Is the support for SOCKS-Proxys not intended to be transitioned to IPv6?