If you are playing a source engine game infected by these fake servers you will see a number of different servers spam your list that will make you end up on a different server than you thought you would join. At the moment of writing the Fastpath community is the primary abuser with this method.

When you joined one of these servers you can still join other servers, but because of the large amount of servers they spam and the fact they can use players joining the servers to fake having a high player amount for a long time it is easy to get trapped back in.

One of the most important reasons to block these servers outright is that by joining them they can use your steam information to fuel their spamming method. They capture your steam details including the unique authentication you used to join the server, and instead of removing this like other servers do when you leave they will instead put your information and nickname on all the other fake servers for as long as your information is valid. Causing these servers to appear very high up the server list making it hard to avoid them for others because they can spam as many as they want.

On top of this they will fake any information they can, different map names, server names, server names of popular servers you like, player numbers and even ping (Although they fake the ping ingame not on the server list). And during the times less HL2DM players are online their effect is amplified since it will be harder for steam's server to detect which server has legitimate players online.

Because they constantly change their details and the ports the servers run on blocking them using the ingame blocking buttons is almost impossible. This guide lists 3 different methods you can use to block the spam properly.

The easiest method to automatically block the servers is to block them in the Windows Firewall, to do this automatically download the GameSpamFilter[content.hl2dm.org] file.

Once downloaded run this file and allow it administrator permissions. It will now automatically download the current list of IP's that need to be blocked, and update your firewall to block these IP's completely.

After running this script you should be able to refresh the server list and no longer see these IP's, if the game you are trying to play uses the steam web API they might still show up, but in that case you will not be able to accidentally connect and they will not show ping.

If they create new spam servers you can run the script again without downloading anything, it will automatically download the new list and update the firewall for you. If the IP still shows up please leave a comment on this guide so i can verify the IP and add it to the list.

Because these servers randomize their ports you can not effectively block them using the ingame Add to Blacklist button. It would be a cat and mouse game where you are constantly adding the servers to the blacklist only to get spammed again later.

Luckily for the players who do not use Windows the game does allow importing the servers without the ports, you will need to obtain the current Blacklist[content.hl2dm.org] .

After downloading the blacklist go to the Blacklisted Servers tab and use the Import to File button, navigate to the downloaded server_blacklist.txt and import. You will now see the blacklisted IP's show up as Spamfilter followed by the IP.

If they put up new IP's you will need to download the blacklist again and repeat these steps.
Just keep in mind this only blocks the servers ingame, on the steam server browser inside steam itself you will still see all the spam if you use this method.

This part of the guide is not going to be step by step, since i do not know which Firewall you have or if it is even enabled. I just like to point out you do not have to rely on either the GameSpamFilter script or the Blacklist and can use your existing firewall on either your PC or your router instead.

If you want to do this you can download all the known IP's here : http://content.hl2dm.org/spamfilter/RogueIPs.txt

Anyone wanting to build a solution with this list is free to crawl it at any time, i have plenty of bandwidth on that server.

To answer the last question first, yes especially the GameSpamFilter method absolutely works on other games from valve (and possibly non valve games to). But since i provide servers for the Half-Life 2 Deathmatch community blocking their HL2DM IP's is my priority so they can technically put up IP's for other games without me noticing.

If you find an IP that redirects to a server you did not intend to join feel free to post a comment on this guide so i can include it to the list. I only do this for servers that belong to communities that spam the server list with fake servers. If a server simply has a lot of bots, even if these bots are disguised as players ingame i will not add it to the list because you can easily avoid this server yourself and some players may enjoy larger bot battles.

If you have any further questions feel free to let me know in the comments.