After very long time using Ubuntu old LTS version I have re-installed to new LTS 12.10, but I can't get rid of ipv6 ! I have did: in /etc/modprobe.d/blacklist.conf: blacklist ipv6 blacklist ip6table_filter blacklist ip6_tables in /etc/sysctl.conf net.ipv6.conf.all.disable_ipv6 = 1 net.ipv6.conf.default.disable_ipv6 = 1 net.ipv6.conf.lo.disable_ipv6 = 1 But ufw happily use v6 protocol, and in dmesg: ip6_tables: (C) 2000-2006 Netfilter Core Team . . IPv6: ADDRCONF(NETDEV_CHANGE): em1: link becomes ready What is going to take to get rid of IPv6 ? I swear Terminator didn't put so much fight.