Linux Hint published a guide about configuring Ubuntu 18.04 LTS as an Ubuntu Package Cache Server.

Configure Ubuntu 18.04 LTS as an Ubuntu Package Cache Server

Apt-Cacher-Ng is a package cache server which caches Ubuntu packages automatically and serves them when the same package is requested more than once. In this article, I am going to show you how to configure Ubuntu 18.04 LTS desktop or server as an Ubuntu package cache server with Apt-Cacher-Ng

Configure Ubuntu 18.04 LTS as an Ubuntu Package Cache Server – Linux Hint