This tutorial will explain how to disable IPV6 in debian.
Open a terminal and su to root
Now you need to check if iPV6 is active or not using the following command
netstat -tunlp |grep p6 |wc -l
If the result is anything other than 0, then one or more IPv6-aware processes is running.
Disable using the following 3 commands
echo net.ipv6.conf.all.disable_ipv6=1 > /etc/sysctl.d/disableipv6.conf
sed ‘/::/s/^/#/’ /etc/hosts >/etc/dipv6-tmp;cp -a /etc/hosts /etc/hosts-backup && mv /etc/dipv6-tmp /etc/hosts
sed ‘/ipv6=yes/s/yes/no/’ /etc/avahi/avahi-daemon.conf >/etc/avahi/dipv6-tmp;cp -a /etc/avahi/avahi-daemon.conf /etc/avahi/avahi-daemon.conf-backup && mv /etc/avahi/dipv6-tmp /etc/avahi/avahi-daemon.conf
After running above 3 commands restart your system
Now you can run the following command to check IPV6 is active
netstat -tunlp |grep p6 |wc -l
Again, these steps will disable IPv6 on a stock install of Squeeze. If you have additional IPv6-aware processes running (server daemons in particular), then additional steps may be required.
That is ugly. How about this instead
edit /etc/sysctl.conf
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1
net.ipv6.conf.eth0.disable_ipv6 = 1