I'm not sure about op, but I actually run Lancache (lancache.net) locally on our network. It supports Steam, Windows Updates, Epic games, and pretty much anything else served over http.. (https://github.com/uklans/cache-domains).

This is all assuming you're not using a domain etc.. and have any of the myriad of other tools setup. We run lancache strictly for the fun-net segmented network.