How to Disable IPv6 (Internet Protocol version 6) on CentOS 8

IPv6 (Internet Protocol version 6) is the latest version of the Internet Protocol (IP) that provides an identification and location for internet devices on networks and provides a larger IP addressing scheme for IoT (Internet of Device). IPv6 is looks like as below on CentOS:

[root@linuxcnf ~]# ip addr show ens33 3: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000     link/ether 00:0c:29:9d:90:e5 brd ff:ff:ff:ff:ff:ff     inet 192.168.43.23/24 brd 192.168.43.255 scope global noprefixroute ens33        valid_lft forever preferred_lft forever     inet6 2405:204:109d:260b:8d49:6d25:fa2b:6ef4/64 scope global noprefixroute dynamic        valid_lft 3247sec preferred_lft 3247sec [root@linuxcnf ~]#

This article describes How to Disable IPv6 (Internet Protocol version 6) on CentOS 8.

Step 1. Change in Configuration: Edit the /etc/sysctl.conf configuration file and append the following parameters at the end of the file:

[root@linuxcnf ~]# vi /etc/sysctl.conf ……………… net.ipv6.conf.all.disable_ipv6 = 1 net.ipv6.conf.default.disable_ipv6 = 1 [root@linuxcnf ~]#

Step 2. Reloading Parameters: Save the changes and run the following command to reflect the changes in the kernel parameters configurations:

[root@linuxcnf ~]# sysctl -p ………….. net.ipv6.conf.all.disable_ipv6 = 1 net.ipv6.conf.default.disable_ipv6 = 1 [root@linuxcnf ~]#

Step 3. Verify the Configuration: Run the following command to verify the status of IPv6 status:

[root@linuxcnf ~]# ip addr show ens33 3: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000     link/ether 00:0c:29:9d:90:e5 brd ff:ff:ff:ff:ff:ff     inet 192.168.43.23/24 brd 192.168.43.255 scope global noprefixroute ens33        valid_lft forever preferred_lft forever [root@linuxcnf ~]#

Done!!! Now IPv6 is disabled from all the interfaces.