At home I have a custom-built NAS that I use for all of my storage needs. I use it all the time to store files like game client downloads and backups of my games on Steam. It just makes it easier to restore after an install or when a friend needs to copy a game over. Recently however I was referred to LANcache.
EDIT 3/2/2017
As pointed out by some commenters, the previous nginx config was incorrect and missing some server names. This post has been updated to reflect those changes.
I had to redo my caching server recently and I can 100% confirm that this guide will work correctly. Nothing like a clean install!
The basic premise of LANcache is there is a computer (or virtualized computer) that sits between you and Steam’s content servers. The computer will listen to any computer on the LAN that requests a download from Steam and jumps in and says “Oh, I’ve got that file right here! We’ll just copy it over the local network so you don’t have to go out to the web to do it.” If it doesn’t have the file stored already, it will start downloading the file from Steam to its drive and then send it to your Steam client at the same time.
This is extremely advantageous as you really only have to download a file once. If you have friends over or do an OS reinstall, a game is only downloaded once saving bandwidth and more importantly, time.
It turns out that LANcache is a fairly straightforward combination of a reverse proxy built with nginx and a DNS server configured to emulate Steam’s content servers. This is easy enough to set up. My server runs Ubuntu, but you should be able to do this with pretty much any OS that supports nginx and BIND. Just make sure that the version of nginx your OS installs is >1.6.0. Anything lower will not have the caching module and you will have to find another way to get it installed.
First we should install nginx and BIND so we can configure it:
sudo apt-get install nginx bind9Installed! Easy enough…
The configuration is pretty straight forward. I will most likely cover how to cache some other platforms (GOG, Origin, Battle.net, etc) in another post, but Steam should be good enough to start. For the configuration we need a few files. I’ll cover each one, their location, and their purpose.
This is the main nginx config file. Here we will define the directory being used for the cache and will tell nginx that it should act as a reverse proxy and cache when hitting certain Steam domains.
server {
listen 80;
server_name *.steamcontent.com *.steampipe.steamcontent.com *.cs.steampowered.com content1.steampowered.com content2.steampowered.com content3.steampowered.com content4.steampowered.com content5.steampowered.com content6.steampowered.com content7.steampowered.com content8.steampowered.com;
access_log /data/Downloads/Cache/logs/access.log;
error_log /data/Downloads/Cache/logs/error.log;
root /data/Downloads/Cache/Steam;
index index.html index.htm;
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root /use/share/nginx/html;
}
proxy_temp_path /data/Downloads/Cache/tmp/ 1 2;
resolver 8.8.8.8;
location /depot/ {
try_files $uri @mirror;
access_log /data/Downloads/Cache/logs/access.log;
}
location / {
proxy_next_upstream error timeout http_404;
proxy_pass http://$host$request_uri;
proxy_redirect off;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
add_header X-Mirror-Upstream-Status $upstream_status;
add_header X-Mirror-Upstream-Response-Time $upstream_response_time;
add_header X-Mirror-Status $upstream_cache_status;
add_header Host $host;
access_log /data/Downloads/Cache/logs/access.log;
}
location @mirror {
proxy_store on;
proxy_store_access user:rw group:rw all:r;
proxy_next_upstream error timeout http_404;
proxy_pass http://$host$request_uri;
proxy_redirect off;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
add_header X-Mirror-Upstream-Status $upstream_status;
add_header X-Mirror-Upstream-Response-Time $upstream_response_time;
add_header X-Mirror-Status $upstream_cache_status;
access_log /data/Downloads/Cache/logs/access.log;
}
}
```
For your own configuration you’ll want to change `/data/Downloads/Cache` to your own directory. If the directory doesn’t exist yet, create it and then create a logs directory inside of it. You’ll also want nginx to pick up on the config from a directory it monitors so create a symbolic link:
sudo ln -s /etc/nginx/sites-available/cache-steam /etc/nginx/sites-enabled/cache-steam
Finally run the following to test your nginx configs. If there’s no errors, then continue to the next section.
sudo nginx -t
#### /etc/bind/db.cache.steam
This file sets up the A records for the DNS server. It’s fairly straight forward. Replace `10.0.1.10` with your server’s local IP (which should be static of course) and replace `pathartl-server` with the hostname of your server.
<pre class="EnlighterJSRAW">; BIND reverse data file
$TTL 86400
@ IN SOA pathartl-server. 10.0.1.10 (
1 ; Serial
604800 ; Refresh
86400 ; Retry
2419200 ; Expire
86400 ) ; Negative Cache TTL
;
@ IN NS pathartl-server.
@ IN A 10.0.1.10
* IN A 10.0.1.10
Now all that’s left is the zone file. This tells clients using our DNS server that Steam’s servers exist at whatever we put in the `db.cache.steam `file.
#### /etc/bind/named.local.steam
//
// Add include "/etc/bind/named.local.steam"; to your named.conf.local file
//
zone "content1.steampowered.com." IN {
type master;
file "/etc/bind/db.cache.steam";
};
zone "content2.steampowered.com." IN {
type master;
file "/etc/bind/db.cache.steam";
};
zone "content3.steampowered.com." IN {
type master;
file "/etc/bind/db.cache.steam";
};
zone "content4.steampowered.com." IN {
type master;
file "/etc/bind/db.cache.steam";
};
zone "content5.steampowered.com." IN {
type master;
file "/etc/bind/db.cache.steam";
};
zone "content6.steampowered.com." IN {
type master;
file "/etc/bind/db.cache.steam";
};
zone "content7.steampowered.com." IN {
type master;
file "/etc/bind/db.cache.steam";
};
zone "content8.steampowered.com." IN {
type master;
file "/etc/bind/db.cache.steam";
};
zone "cs.steampowered.com." IN {
type master;
file "/etc/bind/db.cache.steam";
};
zone "clientconfig.akamai.steamstatic.com." IN {
type master;
file "/etc/bind/db.cache.steam";
};
zone "hsar.steampowered.com.edgesuite.net." IN {
type master;
file "/etc/bind/db.cache.steam";
};
zone "steampipe.steamcontent.com." IN {
type master;
file "/etc/bind/db.cache.steam";
};
zone "steamcontent.com." IN {
type master;
file "/etc/bind/db.cache.steam";
};
As the header of that file pointed out, we need to enable this zone file. Add the following line to `/etc/bind/named.conf.local`
include "/etc/bind/named.local.steam";
## Finishing Up
That should be about it for configuration. Restart your DNS and web server:
sudo service bind9 restart
sudo service nginx restart
There’s only one more step to take. You need to get your computer to use your caching server as a DNS server. There’s tons of tutorials out there to do it on any OS, but I would recommend you make the change in your router. That way anyone that connects to your LAN will download files from your cache. Make sure to set up alternate DNS servers also! Our server will only handle Steam content servers. Other domains (google.com, reddit.com, youtube.com, etc.) will not resolve.
Once you’ve changed your DNS server, go ahead and install a game off Steam. I recommend one <1GB for the initial test. Once it is done downloading, right click the game and hit “Delete Local Content”. This will delete the game off your disk. Next install the game again and watch your download speeds skyrocket! I was able to get some pretty sick speeds when it was all said and done:
[](/user/uploads/2016/07/2016-07-22-23_35_08-Steam.png)