-*- outline -*-

* How disable IPv6?

** Debian kernel 2.6/Ubuntu ("official" method)/Fedora Core.

Comment in /etc/modprobe.d/aliases "alias net-pf-10 ipv6" and add alias
"net-pf-10 off", "alias ipv6 off":

  $ sudo emacs /etc/modprobe.d/aliases
...
  $ cat /etc/modprobe.d/aliases
...
# alias net-pf-10 ipv6
alias net-pf-10 off
alias ipv6 off
...

Reboot or

  $ sudo update-modules

Another way is adding to /etc/modprobe.d/blacklist.local lines

  blacklist ipv6

You can safely wipe out any IPv6 reference in "/etc/hosts" and
"/etc/network/interfaces".

** RHEL4/Centos4.

As for Debian, but "/etc/modprobe.d/aliases" has name "/etc/modprobe.conf".

** KDE.

  $ cat /etc/environment
...
KDE_NO_IPV6=true
...

** Firefox.

See about:config page, set "network.dns.disableIPv6" to "true".