LAN configuration issues

[kipale]

Hello there, I'm having issues with a game called Trackmania United Forever. Me and my buddy wish to play together in LAN, but can't manage to configure the thing correctly. What makes it hard is that we have some issues with licences (I'm using same licence on 2 computers and it's not legal to connect both to internet) so we can't let the application connect to internet, but it must have all needed access to my buddy's computer. My buddy has another licence so that's not a problem.

So... I've made firewall rules on both computers to allow all traffic in IP range 192.168.0.0 - 192.168.255.255, which is our LAN-network and both computers' IP's are on that range, and another rule to block everything else. Still it's not working, the game doesn't see the other computer on the network. It's not possible to connect by direct IP, it must be done via LAN.

So the question is, what connections/rights the application needs to be able to see the LAN-network and the computers connected to it? We both got vista and our comps can see each other in windows network interface.

Sorry for long post

 

[MetalX]

Now I'm quite something of a noob in the networking world, but I have had similar problems before. Usually we solve them with a program called hamachi, which creates a LAN for computers even across the internet. Usually when we cannot get a game's LAN features working, my friends and I just fire up hamachi and it works.

But honestly, I'd wait for one of Techspot's networking gurus to come along and help you with this...

 

[kipale]

Yea I thought of hamachi too. But I remember having similar problems with other games some time ago and I feel like I could as well fix the problem for good. Having the 2 computers next to each other and both connected to same router it feels like hamachi is kind of cheating.

 

[LookinAround]

i think you need start with more information then you've indicated in your thread. Whether you talk about LAN or Internet, it's still an issue using a transfer media which implements a multi-layer protocol. And your specific game / product might operate on a subset those multi-layers. And of course throw in all the optional choices that can be made.

Am not a gamer but would think you HAVE to start at their support site to know (and provide guidance others about) Trackmania's network expectations and and what networking features are uses for their game's functionality

 

[kipale]

Hmm... I suppose you are right. I'm not a networking guru so multilayer protocol with transfer media implement issues sounds scary to me. I know that to actually form the client-to-server connection needed to play it uses only UDP and some port, but I have allowed the program to do all IP-traffic it needs in LAN (that includes the UDP-port). Now since I can't use direct IP, the program has to find the other computer in the network. How does windows do that? If I go to command line and type "net view", how does it come up with a list of computers in my LAN? I mean it can't just ping every possible IP-address, can it? What do I need to do that the game can come up with the same list that windows does?

 

[DelJo63]

Yes, the stupid 'ping every address' is ONE technique that can be used.
However, MS uses port 138 to resolve network system names and port 139,445 for
file/print sharing.

You should anticipate that your firewall(s) need to ALLOW specific ports and BTW:
shutting down the firewall does not ensure that it is totally inactive!

 

[kipale]

Hmm... allright. Thanks everyone, I think this is as much as I can get. I think next I try plugging router off the internet and shutting down all firewalls. Then I can know if it's the firewalls. If it's still not working, then I know it's the router or some other software or windows problem (vista has many funny problems, especially the 64-bit version my buddy has). It might as well be the router, I know it somehow blocks my windows update from working at least (no idea how that is possible when everything else like port forwarding works perfect).

And there's always the option to forget the hassle alltogether and connect directly with twisted RJ45... I think I got one of those cables here somewhere...

 

[kipale]

Ahh, I solved it. As jobeard said my firewall was still active even when shut down. After noticing that I made it log it's actions so I could see what it was blocking. It turned out that you need to allow a program access to UDP outbound 255.255.255.255 port 2350 for it to retrieve a list of hosts connected to LAN. 255.255.255.255 is probably some kind of magic IP that routes the message to every other computer in LAN (like 127.0.0.1 always routes to localhost).

I also found out that my firewall (COMODO) was sometimes blocking Windows Operating System from access to the given connection. So for everyone out there having problems with their LAN-network and using COMODO firewall, just allow "Windows Operating System" and "System" access to UDP 255.255.255.255 port 2350. You also have to give access to the computers in the LAN-network, of course.

 

[DelJo63]

After noticing that I made it log it's actions so I could see what it was blocking. It turned out that you need to allow a program access to UDP outbound 255.255.255.255 port 2350 for it to retrieve a list of hosts connected to LAN.

Well done! This is how you lean about firewalls AND how programs use TCP.
(by the way: remove the port number from the rule; might as well allow all programs to us outbound broadcasting )

255.255.255.255 is probably some kind of magic IP that routes the message to every other computer in LAN

There are a few 'special' IP addresses --- this one of them -- the BROADCAST. Any system
who is interested in port 2350 will respond while all others will ignore.
Another form of broadcasting is tcp or udp to x.y.z.255, where x.y.z is your
lan subnet address. This form will not go beyond your router, so it is a LOCAL LAN broadcast

(like 127.0.0.1 always routes to localhost)

might as well clarify this too. 127.0.0.1 never routes and thus can only be used by localhost

 

[kipale]

Yea I felt a bit stupid afterwards for not using firewall logs in the first place. Strange that COMODO was blocking windows sometimes too, though. The game I understand, but it probably shouldn't go blocking windows like that. Also with COMODO you can't make a global rule to allow 255.255.255.255 broadcasting, since it always overruns global rules with application rules in outbound traffic.

 

[DelJo63]

Also with COMODO you can't make a global rule to allow 255.255.255.255 broadcasting, since it always overruns global rules with application rules in outbound traffic.

It's been a while since I had COMODO install so
I can say yea/nay on this. However, the general principle for all firewalls, is
most specific rules apply first and most general rules apply last. This allows

• deny in tcp src a.b.c.d
• allow in tcp src a.b.c.d port xxx

port xxx access will be allowed while all other ports from a.b.c.d will be denied

Notice: the general rule of application in the order written is retracted in favor of the
specificity rule