Désactiver IPv6

A la volée

 > # sysctl -w net.ipv6.conf.all.disable_ipv6=1
 > # sysctl -w net.ipv6.conf.default.disable_ipv6=1
 > # sysctl -w net.ipv6.conf.tun0.disable_ipv6=1

Au reboot

 > # vi /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.tun0.disable_ipv6 = 1