DNS¶

Your PCs find lanstash through DNS. The LAN's DNS server answers the game CDN host names with lanstash's address, so a launcher that wants a download asks lanstash instead of the internet. This page explains what is needed, how lanstash's DNS page sets it up on AdGuard Home or Pi-hole for you, and how to do it by hand on any other DNS server.

The examples use 192.0.2.10 for lanstash and 192.0.2.1 for the LAN's DNS server.

Why DNS¶

A launcher downloads from host names such as google.epicgamescdn.com. When the LAN's DNS server answers those names with 192.0.2.10, the request reaches lanstash, which serves it from the stash or fetches it once from the real CDN (looked up through upstream_dns) and keeps it. Nothing needs changing on the PCs themselves, apart from Epic's launcher (see First steps).

The names come from the cache-domains lists in your cache_domains directory (see Configure). Each line is written one of two ways:

• name: that one name;
• *.name: every name under it, but not the name itself.

When Epic Games is among the services, lanstash also wants google.epicgamescdn.com and *.google.epicgamescdn.com, which its list lacks.

The DNS page¶

The web UI's DNS page links lanstash to your DNS server, adds the rewrites lanstash wants and checks how the names stand. It works with:

Changing the DNS setup, and even reading it, needs an account with the dns permission (an admin).

Set up the server¶

Under Server, choose Change and fill in:

• Kind: AdGuard Home or Pi-hole.
• Address: its host name or IP address, without http:// (for example 192.0.2.1).
• Connection and Port: how its admin page is reached, plain HTTP or HTTPS, and on which port.
• Certificate (HTTPS only): Check wants a certificate from a public authority for that address; Trust one accepts only the certificate with a given SHA-256, for a self-signed one; Don't check accepts any.
• User (AdGuard Home) and Password. lanstash keeps the password where only it can read it and never shows it again; leave it empty later to keep it.
• lanstash's address: the IP address your PCs reach lanstash at, 192.0.2.10. Left empty, lanstash uses the address your existing rewrites of its names already lead to.
• Point the names at: The address, or A name (every game name points at that name, and that name at lanstash's address, so only one rewrite changes if the address ever does).

Test tries the setup without keeping it; Save tries it, then keeps it. When an HTTPS certificate is not trusted, the page shows its SHA-256 and offers to trust exactly that certificate. Forget removes the setup and its password.

Add the rewrites¶

Rewrites shows how many of the names lanstash wants are rewritten to its address, per platform, with the ones missing, the ones there twice, and the ones the server already sends to lanstash by a rule of its own or a wider rewrite. Add N rewrites adds the missing ones and merges duplicates. It never removes or changes a rewrite that is not lanstash's: one pointing elsewhere, or one pointing at lanstash for a name on none of its lists, is left alone.

On Pi-hole, a rewrite is a reply rule (marked with the comment lanstash) that answers IPv4 queries with lanstash's address and IPv6 queries with ::, so a PC with IPv6 cannot go around the cache.

Check what went around¶

• Went to the internet lists, from the latest lookups the server logged, the names of a cached platform that no rewrite answered, with how often and by which clients.
• Refused by lanstash lists the names sent to lanstash since it started that none of its lists name.

By hand, on any other DNS server¶

On any DNS server that can answer a name with a fixed address, add one entry per line of the lists you use:

Add google.epicgamescdn.com and its subdomains for Epic Games. Make sure IPv6 (AAAA) queries for these names do not lead to the internet, or a PC with IPv6 may download around the cache.

Then check from a PC on the LAN:

nslookup google.epicgamescdn.com 192.0.2.1

The answer should be 192.0.2.10. lanstash doctor checks the upstream DNS; the DNS page's checks need AdGuard Home or Pi-hole.

Next: First steps.