IPV6 sometimes break DNS resolution in Ubuntu 18.04. Follow the steps below to disable and verify
that IPV6 is disabled in Ubuntu.
Edit /etc/sysctl.conf and add the following lines to the end of the file …
net.ipv6.conf.all.disable_ipv6 = 1 net.ipv6.conf.default.disable_ipv6 = 1 net.ipv6.conf.lo.disable_ipv6 = 1
Save the file and issue the following command to force Ubuntu to reload the file.
To verify that the new configuration has been applied, you can issue the next command.
You should receive a result of 1 if it was successfully applied and 0 if it failed.