From MEPIS Documentation Wiki
Disabling Solely In Firefox
The way Firefox configures its use of the internet protocol IPv6 can slow down your connection. To disable IPv6 in Firefox:
- In Firefox in address bar type: about:config
- In Filter field enter: ipv6
- double-click the value for network.dns.disableIPv6 to change it to true
Disabling System Wide
For the 2.6.32 kernel, the procedure below no longer works because ipv6 has been incorporated into the kernel. As a workaround, you can disable it by appending the following as a boot-option to the 'kernel' line of the GRUB menu:
MEPIS 8.0 or older
Since other applications such as Opera or Thunderbird can also experience this slowdown, you may want to turn off IPv6 system-wide.
- Open a Filer Manager Session - Super User Mode
(KDE-Start> System> File System> File Manager Super User Mode)
- Navigate to directory /etc/modprobe.d
- Right click in empty space in the browser window and choose Create New > Text File ....
- Name the new file 00local.conf (that's zero zero .... and no 3 letter .extension at end)
- Open the file by clicking on it (still in SuperUser Filemanager) and paste these two lines:
alias net-pf-10 off alias ipv6 off
- Save and close the file
You can TEST whether ipv6 has indeed been disabled by issuing the root cmd:
ip a | grep inet6
and you should NOT see any output from that command.