IPv6 still enabled

[cam17]

I am using 18.04 Desktop and have WIFI IPV6 disabled in the wifi configurations. but when I go to the "details" tab it shows an IPv6 address as if disabling IPV6 had no affect.

[1fallen]

The only way "I" have found to disable "IPV6" is to do so via grub:

sudoedit /etc/default/grub

And add to this line:

GRUB_CMDLINE_LINUX_DEFAULT="quiet ipv6.disable=1"

So you will need to add "ipv6.disable=1" save and close, and then run:

sudo update-grub

Now after a reboot you should have IPV6 disabled, and check this for verification:

sudo sysctl -a|grep disable_ipv6
[sudo] password for me: 
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.enp0s25.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1
net.ipv6.conf.tun0.disable_ipv6 = 1
net.ipv6.conf.wlp3s0.disable_ipv6 = 1

[Doug S]

The only way "I" have found to disable "IPV6" is to do so via grub:

I do the same as 1fallen.

[cam17]

I understand what your saying 1fallen but the grub is for boot up paramaters the operating system should override the settings once up and running. This should be corrected as Ubuntu has the option to turn opv6 off but it does not work.

[The Cog]

I understand what your saying 1fallen but the grub is for boot up paramaters the operating system should override the settings once up and running. This should be corrected as Ubuntu has the option to turn opv6 off but it does not work.

How do you think you have disabled it? I can't find a setting to disable IPv6, only to ignore the interface, enable DHCP or to add additional IPv6 addresses.

[1fallen]

This should be corrected as Ubuntu has the option to turn opv6 off but it does not work.

You will have to show me that one. ignore and disable have two very different meanings here.

[The Cog]

These are the settings I could find:

[deadflowr]

Gnome control center looks like this


Older control center layout had it marked as ignore.
(Like that used by unity)

[SeijiSensei]

Edit the file sysctl.conf as root with the command "sudo nano /etc/sysctl.conf". Add these two lines to the bottom of the file:

net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1

Reboot. You should no longer see an IPv6 entry if you use "ifconfig".

[1clue]

Just out of curiosity, what's your motivation in disabling ipv6? Is it just a lack of understanding of what's involved, or a security issue, or something else?

If you're worried about a security issue, then turning off IPV6 at the router will likely be all you need. But that said, if you want to be extra safe you could do what everyone else is saying.

Your ISP may not supply IPV6 access anyway, you can find out by looking for global addresses:

$ sudo ip -6 address list
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 state UNKNOWN qlen 1000
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: enp3s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 state UP qlen 1000
    inet6 dad:ea75:dead:beef:3cd0:a325:e5c2:976f/64 scope global temporary dynamic 
       valid_lft 541585sec preferred_lft 23136sec
    inet6 fe80::406:100e:3594:9b6c/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever

If you don't have global addresses then your router doesn't supply ipv6 functionality, or your ISP doesn't.

If your addresses start with fe80 then they will never be accessible on the public Internet.