How to disable ipv6 system-wide?

[dasuberadmin]

When I re-enable ipv6 by modifying /etc/sysctl.conf and removing the added directives and rebooting afterwards the cockpit service comes back online.

But as soon as I either follow

How to disable ipv6 system-wide?

To disable system wide ie centos7 iirc echo "net.ipv6.conf.all.disable_ipv6 = 1 net.ipv6.conf.default.disable_ipv6 = 1" >> /etc/sysctl.conf && sysctl -p Should work Almost forgot to avoid SSH issues echo "AddressFamily inet" >> /etc/ssh/sshd_config && systemctl restart sshd

or

Postfix tries to connect to IPV6 servers and gets "Network unreachable" error

To disable ip6, please try: # check ipv6 ifconfig -a | grep inet6 # make folder for template mkdir -p /etc/e-smith/templates-custom/etc/sysctl.conf # create template-file nano /etc/e-smith/templates-custom/etc/sysctl.conf/99sysctl # content of 99sysctl net.ipv6.conf.all.disable_ipv6 = 1 # expand template expand-template /etc/sysctl.conf # To reflect the changes sysctl -p # check ipv6 again ifconfig -a | grep inet6

and reboot the cockpit service dies again with the
cockpit.socket failed to listen on sockets: Address family not supported by protocol
error message.

My WAN interface is getting a DHCP address from my router which does not support IPv6.

The reason I want to disable IPv6 entirely is that it is of no use in my internal network for the reason stated above and in my original post.

When I try to enable the smart host the logs don’t show anything except timeout for the INET6 reason.