Centos 7 with IPV6 at Server4You

As of 2019-10-01, the hosting company server4you.com doesn’t support IPv6, but if you want to test IPv6 or support your IPv6 capable clients there are still a few tricks you can try.
A good way is to use a broker to create a 6in4 tunnel with your IPv4 to the IPv6 enabled internet.

***** Disclaimer *****
 
This guide DOES NOT WORK if you are using their offerings of the vServer family because it’s powered by OpenVZ, but it will work perfectly with the VDS family powered by KVM or with their dedicated servers.
This is NOT a “true” IPv6 solution as you will use a tunnel broker to make a 6in4 tunnel, but it gets the job done for most workloads.
 
***** End Of Disclaimer *****
 
You start by creating an account at Hurricane Electric and then creating a tunnel there pointing to your server IP address, you should preferably choose a tunnel server that is near your server but this is not strictly necessary.
Continue reading “Centos 7 with IPV6 at Server4You”

Force apt-get to use IPv4

If you are having problems with apt and IPv6 a temporary solution is to use the option ‘Acquire::ForceIPv4=true’ by appending ‘-o Acquire::ForceIPv4=true’ at the end of the apt command.

apt-get update -o Acquire::ForceIPv4=true

 
If you want a more permanent solution you can disable the usage of IPv6 with apt altogether with:

echo 'Acquire::ForceIPv4 "true";' | tee /etc/apt/apt.conf.d/99force-ipv4

 

Sources:

https://unix.stackexchange.com/questions/9940/convince-apt-get-not-to-use-ipv6-method

Disable IPv6 on Linux Via Kernel Boot Parameters

If for any reason you want to disable ipv6 and don’t want to do it with the sysctl directive, another easy route is to append ‘ipv6.disable=1’ to the kernel boot parameters.

The grub Way

Open /etc/default/grub and edit the line that starts with GRUB_CMDLINE_LINUX_DEFAULT.
Add the entry ‘ipv6.disable=1’ to the arguments that are already there.
Save and run

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Disable IPv6 on Linux Via Kernel Blacklisting

If for any reason you want to disable ipv6 and don’t want to do it with the sysctl directive, if your kernel was compiled with ipv6 support as a module one easy route is to blacklist the ipv6 kernel module.

All you need to do is create/update the ‘/etc/rc.modules.d/blacklist.conf’ file and add the line ‘blacklist ipv6’.

alternatively you can run the following command as root.

echo '
#Disabling IPv6
blacklist ipv6
' >>  /etc/modprobe.d/blacklist.conf

Sources:

https://www.linuxquestions.org/questions/slackware-14/how-do-i-disable-ipv6-in-slackware-14-1-a-4175504618/
https://www.linuxquestions.org/questions/slackware-14/how-to-disable-ipv6-937447/

Disable IPv6 Centos/Debian/Ubuntu

To completely disable IPv6 on your Linux system, side note you shouldn’t but it’s your choice, you can do so simply editing the 99-sysctl.conf file at the location ‘/etc/sysctl.d/99-sysctl.conf’
 
Copy and paste the following 3 lines at the bottom of the file.

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

 
After editing the file you need to then reboot the machine or run the following command as root

sysctl -p

To verify that you have ipv6 disabled you can run

Continue reading “Disable IPv6 Centos/Debian/Ubuntu”