Server disconnects when 2 computers are playing on the same server.

Carbon14 · May 15th, 2009, 02:35 AM

I seem to have a problem where when me and my brother are playing we will both get "connection problems" at the same time if we are on the same server. If we play separately on different servers we can play for hours without a problem. It's actually fairly irritating considering we both bought the game so we could play together..... Does anyone have any ideas as to a possible fix? It's extremely frustrating. I also am not sure, but we might be crashing the server as well, considering after he has disconnected and we have both timed out I cant seem to reconnect to the server?

Iggy · May 15th, 2009, 12:30 PM

Are both you and your brother connecting from the same Internet connection> Meaning, are you in the same house when you try to play?

Carbon14 · May 16th, 2009, 12:46 AM

Originally Posted by Iggy

Are both you and your brother connecting from the same Internet connection> Meaning, are you in the same house when you try to play?

Yes we are, through router and cable modem. However we have never had a problem playing any other source games at the same time, and as I said we can be playing at the same time on different servers no problem, its only when we are on the same one.

Straight Cash · May 16th, 2009, 12:57 AM

I've never heard of this issue before? Are all your ports forwarded for both IPs? If not that is causing the issue.

Iggy · May 16th, 2009, 01:00 AM

And it happens on multiple servers? I wonder if there is some setting that does not like 2 game clients connecting from the same IP address.

Iggy · May 16th, 2009, 01:03 AM

Originally Posted by Platinum Ninja

I've never heard of this issue before? Are all your ports forwarded for both IPs? If not that is causing the issue.

I don't know that forwarding ports would make any difference. I don't have any ports forward on my router at all, for any game, and I have no problems playing. The only time you should have to forward ports is if you are hosting a server.

I know Steam suggests you forward certain ports to avoid "certain problems", but I have never seen what those certain problems are.

Carbon14 · May 16th, 2009, 02:54 AM

Originally Posted by Platinum Ninja

I've never heard of this issue before? Are all your ports forwarded for both IPs? If not that is causing the issue.

No I haven't done any port forwarding, I will try that I suppose!

Originally Posted by Iggy

And it happens on multiple servers? I wonder if there is some setting that does not like 2 game clients connecting from the same IP address.

Multiple servers, it's simply not really possible for us to play a single campaign on the same server, usually it drops out within the 1st or 2nd map. This is on close servers too, where we are both getting 20 to 30 ping before the problem occurs. Maybe the port forwarding will fix it, who knows, although I am doubtful since as you said it shouldn't have an impact I would have thought.

Iggy · May 16th, 2009, 11:38 AM

Originally Posted by Carbon14

No I haven't done any port forwarding, I will try that I suppose!

Multiple servers, it's simply not really possible for us to play a single campaign on the same server, usually it drops out within the 1st or 2nd map. This is on close servers too, where we are both getting 20 to 30 ping before the problem occurs. Maybe the port forwarding will fix it, who knows, although I am doubtful since as you said it shouldn't have an impact I would have thought.

Well, the fact that you are able to play 1 or 2 maps suggests that it is not a server setting or port forwarding. My experience has been that it is all or nothing when it comes to ports.

I think this is some other kind of connection issue, but I am not sure what it could be.

Maybe post something in the Steam forums?

Deputy_Swan · May 20th, 2009, 12:12 AM

I was Googleing and found this thread, exactly the same problem I am having, 2 brothers trying to connect from same IP and one or the other does not load into the same server when we join, but we can play 2 separate ones all day long no problems

This is annoying problem and i would love some HELP!!!!

Carbon14 · May 27th, 2009, 01:21 PM

well, unfortunately I can tell you we have been unable to remedy the problem. The only slight hint I got was at one point an error was in the console saying something about a "packet split" at "IP blah blah" I didn't check if it was our IP tho..

Iggy · May 27th, 2009, 02:13 PM

Originally Posted by Carbon14

well, unfortunately I can tell you we have been unable to remedy the problem. The only slight hint I got was at one point an error was in the console saying something about a "packet split" at "IP blah blah" I didn't check if it was our IP tho..

Without seeing the rest of that error, it is hard to tell, but my guess is that there is something about their server code that gets confused when it tries to deliver IP packets to 2 different game clients on the same public IP address.

Sorry, I just don't have an answer for you.

Geekman62 · June 3rd, 2009, 01:19 AM

My son and I both have purchased a copy of Left 4 Dead. We can both play simultaneosly as long as we're in different servers. We can not play on the same server. We both hang when the game is starting until one of us aborts and then the other can play. Otherwise we both timeout waiting to get into the server. We are both accessing the internet through the same router, so although our local segment IP address is different, our external IP address is the same. I would appreciate any help you could give.

doom guy · June 7th, 2009, 05:19 AM

Update the firmware of the router - firewall you are using, that might fix the problem.

I was having the same exact problem a few years ago, but with team fortress classic. My kids and I were trying to play some tfc on the same server, but were having problems staying connected. I trouble shot everything on the network, contacted the server owner,,,,, and when I updated my netgear routers firmware - it fixed the problem.

Carbon14 · June 10th, 2009, 04:56 AM

Originally Posted by doom guy

Update the firmware of the router - firewall you are using, that might fix the problem.

I was having the same exact problem a few years ago, but with team fortress classic. My kids and I were trying to play some tfc on the same server, but were having problems staying connected. I trouble shot everything on the network, contacted the server owner,,,,, and when I updated my netgear routers firmware - it fixed the problem.

hmm, I checked my router and it's firmware is all up to date. Is there any way to contact valve about such things? it seems really unfortunate that people have trouble playing a coop game like this with their family. Maybe I will just have to look into buying a new router and modem, who knows.

doom guy · June 10th, 2009, 01:14 PM

Originally Posted by Carbon14

hmm, I checked my router and it's firmware is all up to date.

A couple of things to consider, how old is the router, what brand name is it and is it still supported? If the router is 8 years old, and the last firmware update was 6 years ago, it might be time to update.

I can only tell you that I had the same problem, but with a different game - team fortress classic, which is also a steam game. Updating my routers firmware fixed my connection problems. And now, my 2 kids and I can play TFC, Fortress Forever, Counter-Strike:Source and Left 4 Dead with no problems.

Iggy · June 10th, 2009, 04:33 PM

@doomguy - thanks...very interesting.

@carbon14 - Can you determine how old your router is? Like Doomguy says, it may be time for an upgrade.

Carbon14 · June 12th, 2009, 12:40 PM

Originally Posted by Iggy

@doomguy - thanks...very interesting.

@carbon14 - Can you determine how old your router is? Like Doomguy says, it may be time for an upgrade.

It's only maybe a year or two old, and is a linksys, I would have thought it should be ok :S

Iggy · August 11th, 2009, 11:21 AM

I know this is an old thread, but this appears to be the answer to using two PC in the same household with the same public IP address.

How can I have multiple clients playing games behind a router at the same time?
Answer

To configure multiple clients to play from behind the same router, you must change one of the clients to use a different clientport number.

* Each machine must have a unique Steam account with different game licenses registered to the account.
* Each machine must have a different clientport setting.
* Each machine must have a unique Mac address.
* The router must be up-to-date.
* Your Firewall and router must have the required ports for Steam open.

The default clientport is 27005 and you can only have one game with that port active on the same lan.
Specifying a Clientport as a Launch Option

To specify a client port, please perform the following steps for each computer on the LAN

* Go to Steam's My games menu
* Right-click on the game you wish to play
* Go to Properties
* From the General tab, click on the Set launch options button
* Add a different client port number on each machine between 27005 and 27032 in the following format:
+clientport 270XX
Note: Do not use 27020
* Click OK

NOTE: This solution only works if you launch the game through the My games menu.

If you have already set other launch options, leave a space between the last character of your previous launch option and the + of your clientport setting.
Specifying a Clientport in the Userconfig.cfg

The benefit of this method is that the clientport will remain set whether you are launching the game from the My games menu or from a shortcut to the game.

* Navigate to the folder that holds the config.cfg for your game
Example: The config.cfg for Counter-strike: Source can be found here:
..\Steam\steamapps\<user name>\counter-strike source\cstrike\cfg
* If you have a userconfig.cfg in that directory, open it. If you do not already have a userconfig.cfg:
1. Right-click in the folder
2. Go to: New > Text Document
3. Rename the file userconfig.cfg
4. Open the file with Notepad
* Type into the document clientport 270XX where XX are the last two digits of the clientport number. Acceptable values include 05 - 19 and 21 - 32
* Save your userconfig.cfg
* Launch your game

Server disconnects when 2 computers are playing on the same server.

Problems and Errors: Technical issues or difficulties running Left4Dead or Left4Dead2 on your computer or XBox.