It has happened to some games (CS:GO, Garry's Mod, Age of Empires 3, maybe some others that I haven't tried). My friend just can't connect to my hosted games and I can't connect to his, but with other people it works fine. But in some games he can join (Space engineers).

And now he or I cant even join in the same server no matter who's hosting. Whats happening?! (this only happens in AoE 3, so far)

Some extra info:

We're both running Windows 7 Ultimate I guess we do have an Exteranl IP address but most of the servers aren't the dedicated ones , they're the ones that you just press host game and friends join you.

Now I tried and with Dedicated servers he can join just fine so its just with the Game hosted servers I guess.

Do I need to port forward for a non-dedicated server? I think that i dont have to

And atleast in Age Of Empires 3 we cannot join random servers together , only one of us can be in a server.

  • 1
    I'm afraid there isn't enough information in your question to give specific answers. You could provide more details by answering these questions: what OS are you both running? Does either of you have an external IP? Have you set up port forwarding? Can either of you join a different (random) server? Feb 26, 2014 at 19:20
  • 1
    Are you both on the same network? If not, you'll probably need to do some port forwarding to get it to work right. If you are both on the same network, and try to join the same external game, chances are good it won't allow it due to it coming from the same IP.
    – Frank
    Feb 26, 2014 at 21:11
  • 1
    It sounds like you shared your AoE3 key with your friend.
    – Mazura
    Oct 26, 2015 at 8:20

4 Answers 4


First, check your firewalls and similar programs that could be blocking the connection, second, check your connectivity or Network Address Translation (NAT). NAT adds security to the network by keeping the private IP addresses hidden from the outside world. There are three NAT types to describe your connectivity to other players over the Internet:

Open NAT - This means that your gaming console has the ability to connect to anyone’s games, host games, and other users will be able to find and connect to the game you are hosting.

Moderate NAT - This means that your connectivity to other players is neither limited nor open. You will be able to connect to other players but some functions will be limited.

Strict NAT - This means that you have limited connectivity with other players and players who have Strict or Moderate NAT will not be able to join your gaming session.

  • 1
    I believe this is incorrect. NAT on its own does not add much security other than acting as a de-facto stateful firewall. Rather than security it's often used to allow interfaces with LAN-only addresses to communicate with external networks. The configurations you describe area also ambiguious. Wikipedia offers a brief summary of configurtations: en.wikipedia.org/wiki/… May 28, 2014 at 2:13

This problem can have various causes, so I will develop only what I think are the two main ones:

The Windows Firewall

First make sure that the Windows firewall is not the cause. You should see AoE3's launcher in the firewall's list (which you can find in "Start → Control Panel → System and Security → Allow a Program through Windows Firewall" under Windows 7). Ensure that the checkbox at its left is checked, along with the "private" or "public" one at its right. In general the "public" checkbox should be enough if you are connected to a private network (I assume you are at home and not on a public computer). If you are not sure though, just check both boxes related to AoE3 and try to host a game again.

NAT and Ports Forwarding

If that doesn't work, I certainly has something to do with your router. I wouldn't recommend DMZ-ing your computer as it is a huge security risk. Instead, you will want to forward ports from your router to your computer. The procedure is different for each router, so what follows is a general overview of what you will need to do:

  • First connect to your router's web interface
  • On some routers you may have to activate "expert" or "advanced" mode to access the NAT and port forwarding settings
  • Access the NAT/port forwarding section of the web interface
  • Some routers will have a pre-defined list of programs that you can use to add an array of ports to the router's port forwarding rules, in this case try to see if AoE3 is in it and add the rule to forward to your computer (you may need to know the local IP address of your computer to do so)
  • If you don't have this pre-defined list, you will have to add the rules manually. The ports to add are the following (always using your computer/IP address as the target):
    • TCP port 80
    • TCP port 2300
    • UDP port range from 2300 to 2310

This list is a courtesy of this article

Your friends will need to use your public IP address to connect to your server, you can find that by Googling "What's my IP". If this does not work, you may have a special configuration / other problems that prevent your friend to connect.


Make one of the computers dmz host on the router. This will clear up the problem you are describing.


  • It'd be a lot safer to figure out what ports to open, than to be naked on the internet.
    – Mazura
    Dec 20, 2016 at 0:11

I would suggest try disabling every piece of security you have and slowly start making them active again.

This way you can isolate the cause.

Disable OS firewall, DMZ your computer from the router or modem your connected from and incase you have a router also let the modem dmz the router. Unless you have a multi modem, in that case you only need to dmz your computer

This way you have a 100% passage way without hinderance, this leaves you open to attacks tho but its only short testing purpose, when you know your friend can join simply put 1 piece of security back up and try to reconnect. If it works you can enable the other piece of security and so on till you found the cause.

I would suggest to run from the modem to your computer. first remove dmz from your modem to router second remove dmz from router to computer turn on firewall on pc.

This is the most common setup for home but if there is more you want to disable those as well.

Most cases its a portforward which mostly need to happen on both the modem and the router. Sometimes you also need the ports setup in your firewall depending what firewall you use and how you have set the rules for it.

Im pretty sure this will help you out and google is your friend for your modem/router/firewall types since every modem/router/firewall is different.

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