Force IPv4 when using APT command in Ubuntu

Sometimes you may want to disable IPv6 when using apt update command or some other apt operation.

If you want to use IPv4 in one command, just run following:

$ sudo apt -o Acquire::ForceIPv4=true update

If you want to force to use IPv4 for all apt operations, add a new file under /etc/apt/apt.conf.d/

$ sudo nano /etc/apt/apt.conf.d/99force-ipv4

Then add a line:

Acquire::ForceIPv4 "true";

If you want to disable IPv4, change the IPv4 to IPv6.