Making GMod multiplayer work. [Resolved]

Hi. I bought GMod some time ago, but I never got a listen server working until yesterday. I opened some ports (27015-27020 and 1200) on my firewall and my router, but it didn’t work. It only worked when I disconnected my firewall, but I don’t like this solution.

How can I set permissions on the firewall to my GMod to play multiplayer without disabling it? I tried to add these ports to the port sets, and then I added “allow all incoming and outgoing requests” and “allow TCP or UDP in/out from MAC any to MAC any where source port is in [Port set fopr GMod] and destination port [Port set for GMod]”, but it doesn’t work until I disable my firewall. How can I configure it to play without disabling COMODO?

Opening a port has two instances. First step is in Global Rules to make a rule that allows incoming traffic at the requested port(s).

Second step is to make a policy for the GMod application. Easiest for testing is to give it the Trusted Application policy. Make sure this rule is somewhere above, if present, the All Applications rule. When needed drag and drop the rule to a place somewhere above this rule.

I added “allow TCP or UDP in/out from MAC any to MAC any where source port is in [Games] and destination port is in [Games]” to the global rules and the I set hl2.exe as a trusted application on the top of the list, but it still doesn’t work. What can I do?

I assume you made it in Global Rules?

Please change the rule to Allow TCP or UDP IN. Making a rule for IN/Out does not work properly. Outgoing traffic is allowed by default so a rule for outgoing is not necessary. If you want to make a rule for port X in Global Rules that deals with both incoming and outgoing traffic you need to make separate rules for both.

I added “UDP in, blabla”, “TCP in, blabla” and tryied. It didn’t work. Then I tried to add “UDP out” and “TCP out” to global rules, but it still doesn’t work. Maybe it’s because it says “MAC any” and it should be “IP any”?

You cannot map a MAC address on another computer on the internet as MAC addresses don’t get routed over the internet. You can use MAC address when making rules for accessing other computers in your local network.

So that’s the problem… how can I put it to be IP any? I see the other global rules with “IP any”, but when I try to edit them to know how are configurated, the setting shows “Any address” as source and destination, but I also have it like that on my settings and they only show as “MAC any”. What can I do to fix it?

From the Wiki

UDP 1200 1200
UDP 26901 26901 (This will allow the server to show up on the master server list.)
UDP 27000 27015
TCP 27020 27039
UDP 27015 27015 (you may not be able to open this one, but it is suggested that you try)
UDP 27020 27020
TCP 27015 27015

You need firewall rules as follows -
The pattern is -
Source Addr. - Dest.Addr. - Source Port - Dest. Port

Under Global Rules -

Allow UDP IN Any - Any - Any - port 1200
Allow UDP IN Any - Any - Any - port 26901 - (optional if want to show on master server list)
Allow UDP IN Any - Any - Any - port 27000
Allow UDP IN Any - Any - Any - port 27015
Allow UDP IN Any - Any - Any - port 27020
Allow TCP IN Any - Any - Any - port 27020
Allow TCP IN Any - Any - Any - port 27015

Under Application Rule for your server -

Allow TCP/UDP In/Out Any - Any - Any - Any

And trust the app to use only what it needs. (Very Loosey Goosey)


Repeat the global rules verbatim. Then Add

Allow UDP Out Any - Any - port 1200 - Any
Allow UDP Out Any - Any - port 26901 - Any - (optional to work with master server list)
Allow UDP Out Any - Any - port 27015 - Any
Allow UDP Out Any - Any - port 27020 - Any
Allow TCP Out Any - Any - port 27039 - Any
Allow TCP Out Any - Any - port 27015 - Any

If you like.
The Bolded Any’s may be replaced with you/your servers IP (if static) or MAC Address.

I know this seems very long handed but it is basic and should be sure fire.
You have to be very careful when mixing rules for expediency as it is very easy to create broken rules.
As I think may have happened here.

Hope this helps.


Ok, I’m sorry for not answer before, but I was a bit busy. I think I have te correct settings, but I fail at one point: I don’t know how to put “IP any”. Everytime I put “any address”, my firewall configures it as “MAC any”, and I can’t do nothing to put it as “IP any”. Maybe I could configure it to allow IPs from to, but I don’t know if it’s a good idea.


MAC any is OK to use. It allows for IPv6 addresses, so don’t worry about it.

The main thing is , Does it work with these rules now?


Tomorrow I will test it. Now I haven’t friends online so I can’t try if it works or not. I configurated just like you said (with the complicated way, lol). I think it will work now, but we will know it tomorrow.

I’m sorry, I couldn’t reply because I was too busy. Well, now it works fine. Thanks for the help.

You’re welcome.

Marked [Resolved]