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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.

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2 Answers 2

If you really want to disable IPv6, which I think is a bad idea, you need to tell all programs that use the net not to use IPv6. In UFW you have to edit /etc/defaults/ufw and check that IPv6 are not enabled there. But really, I think that's a bad idea.

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Why would it be bad idea ? I do not use IPv6 at all, so why bother kernel and OS with it.. :) but thanks for /etc/defaultufw I have disabled ipv6 there now –  VladoPortos Oct 26 '12 at 8:58
Because all modern OS will have support for it. All programs that connect to net will have it activated. So it would be better to close all connections through IPv6 with ufw then to try to fight all comming upgrades/installations. Because IPv6 has come to stay, and not need to fight NAT is a bliss. If you don't have an IPv6 address that starts with an 2, you don't have a global address and can't connect and be connected to Internet. Lastly, it's not a bother to the kernel. Not compared to a desktop. –  Anders Oct 26 '12 at 9:18
Well maybe, I just don't like things to be on server that are not in use... –  VladoPortos Oct 26 '12 at 10:22
PS: watch out if you disable IPv6 support in ufw. If the ipv6 module is loaded in some other way it will result in a system with IPv6 enabled but without an IPv6 firewall. It's better to leave IPv6 enabled and secure. More and more applications and protocols are using IPv6 these days, even if just on the local link (the addresses that start with fe80: are always available on every interface). –  Sander Steffann Oct 26 '12 at 15:17
And if my solution was good and worked, it would be nice if you marked the answer as a solution. ;-) –  Anders Oct 29 '12 at 7:57

To disable ipv6 just add "ipv6.disable=1" to Your kernel line in Grub...

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