Completele failure connecting to a intra-LAN server

[capnez]

This evening I tried to play Defcon with my brother. I was at my parents' house, so we used our LAN here (which uses a Netgear FVS328 Ethernet router). I know it worked before (way back when Defcon was just a few days old, we did not play since then). However, today, nothing worked. I could not join games he started and vice versa. We disabled all software firewalls, switched the "Enable Port Forwarding" setting in the Defcon Network Options back and forth. We were able to see each other at times in the server browser, but when we tried to connect, we would just get lots of fruitless attempts. Interestingly, when I advertised the game on the Internet but protected it with a network password, he got as far as the password prompt, but only a lot more connection attempts followed. Also, both of us were able to join the same Internet game and chat there. All attempts to do anything only within the LAN failed, unfortunately. We finally gave up.

Maybe someone here can help me and resolve the issue or at least tip me into the right direction.

As for the setup:
Our LAN router/gateway is 192.168.123.100.
My computer was 192.168.123.102, my brother's was 192.168.123.106
In the router, I enabled port forwarding to both computers (where each computer uses different ports - I use the standard ports, my brother's some others that I do not remember at the moment). As I said, both of us could join a hosted game just fine.

This is my debug.txt (I removed my auth key, the last three digits of my keyID and the last two octets of our public IP address):

Code: Select all

Defcon 1.43 built Jul  2 2007
Parsing archive main.dat...DONE
Found installed mod 'samsonov v1.0' in 'mods/samsonov/' 
WinSock started
Client listening on port 5011
Parsing Coastline data (1776 islands) : 54ms
Parsing International data (2753 islands) : 22ms
Parsing City data (2745 cities) : 30ms
Parsing archive sounds.dat...DONE
Authentication key set : 'XXXXXX-XXXXXX-XXXXXX-XXXXXX-XXX'
WinSock started
Connection established to MetaServer, listening on Port 5009
Requesting data from MetaServer : LatestVersion
Requesting data from MetaServer : MOTD
Received data from MetaServer : LatestVersion
Received data from MetaServer : MOTD
Requesting authentication of key XXXXXX-XXXXXX-XXXXXX-XXXXXX-XXX
CLIENT : Disconnected
EclRemoveWindow failed on window LOBBY
Local IP address is: 192.168.123.102
WinSock started
Server started on port 5010
CLIENT : Attempting connection to Server at 192.168.123.102:5010...
Int Data not found : dr
SERVER: New Client connected from 192.168.123.102:5011 (version 1.43)
SERVER: Client at 192.168.123.102:5011 requested ID.  Sent ID 0.
Largest server letter sent : 76 bytes
Received Authentication : XXXXXX-XXXXXX-XXXXXX-XXXXXX-XXX : (keyID 57XXX) : Accepted
Started requesting public IP:port for socket 1220
MetaServer : WAN registration enabled
Authentication HashToken set to -997179974
MetaServer enabling UDP broadcast for LAN discovery...SUCCESS
CLIENT : Received ClientID of 0
CLIENT : Server version is 1.43
MetaServer : LAN registration enabled
Socket 1220 identified as public IP 81.217.XXX.XXX:5010
Server has set the MOD path: ''
CLIENT : Received HelloClient from Server
Requesting data from MetaServer : UpdateURL
SERVER: New team request from 192.168.123.102:5011
Largest server letter sent : 83 bytes
Received data from MetaServer : UpdateURL
Requesting data from MetaServer : DemoLimits
Received data from MetaServer : DemoLimits
Largest server letter sent : 87 bytes
Stopped requesting public IP:port for socket 1220
MetaServer : WAN registration disabled
Started requesting public IP:port for socket 1220
MetaServer : WAN registration enabled
Requesting data from MetaServer : ServerTTL
Socket 1220 identified as public IP 81.217.XXX.XXX:5010
Received data from MetaServer : ServerTTL
CLIENT : Sending disconnect...
CLIENT : Disconnected
SERVER : Shutting down...
SERVER : Sent Disconnect to client 0
SERVER : Shut down complete
MetaServer : WAN registration disabled
MetaServer : LAN registration disabled
NetSocketSession::WriteData write call failed
MatchMaker encountered error sending data
Disconnected from MetaServer
Connection established to MetaServer, listening on Port 5009
CLIENT : Disconnected
EclRemoveWindow failed on window LOBBY
WinSock started
Server started on port 5010
CLIENT : Attempting connection to Server at 192.168.123.102:5010...
Started requesting public IP:port for socket 1276
MetaServer enabling UDP broadcast for LAN discovery...MetaServer : WAN registration enabled
SUCCESS
Requesting data from MetaServer : ServerTTL
MetaServer : LAN registration enabled
Received data from MetaServer : ServerTTL
Socket 1276 identified as public IP 81.217.XXX.XXX:5010
Int Data not found : dr
SERVER: New Client connected from 192.168.123.102:5011 (version 1.43)
SERVER: Client at 192.168.123.102:5011 requested ID.  Sent ID 0.
CLIENT : Received ClientID of 0
CLIENT : Server version is 1.43
Server has set the MOD path: ''
CLIENT : Received HelloClient from Server
SERVER: New team request from 192.168.123.102:5011
Requesting data from MetaServer : ServerTTL
Received data from MetaServer : ServerTTL
Requesting data from MetaServer : ServerTTL
Received data from MetaServer : ServerTTL
CLIENT : Sending disconnect...
CLIENT : Disconnected
SERVER : Shutting down...
SERVER : Sent Disconnect to client 0
SERVER : Shut down complete
NetSocketSession::WriteData write call failed
MatchMaker encountered error sending data
MetaServer : LAN registration disabled
Disconnected from MetaServer
Connection established to MetaServer, listening on Port 5009
CLIENT : Disconnected
Disconnected from MetaServer

I have two further questions:
1.) What exactly does the "Enable Port Forwarding" option in the Network menu do?
2.) Are port ranges changed or reset with an update? I updated my brother's Defcon version to 1.43 just prior to our attempt to play, to maybe it reset the ports? I honestly did not pay attention to that... :-/ However, I do not think this should make a different as long as we are on the same LAN and not separated by a NAT.

Thank you very much!

[edit] Changed something that did not make much sense.

[KingAl]

Without having read the debug log - are you using the same authentication key? If so, all you need to do is remove the key from one of the copies, and they should connect to eachother fine.
Port forwarding is a setting related to NAT-enabled routers allowing external connections. The security risk in enabling it is minimal, really, so it's probably a good idea to have it turned on.

Also, this is worth looking at.

[capnez]

Without having read the debug log - are you using the same authentication key? If so, all you need to do is remove the key from one of the copies, and they should connect to eachother fine.
Port forwarding is a setting related to NAT-enabled routers allowing external connections. The security risk in enabling it is minimal, really, so it's probably a good idea to have it turned on.

Also, this is worth looking at.

Thank you for your help. No, we do not use the same auth key. UPnP is disabled in the router (and always has been). I'm fairly experienced with networking (albeit not professionally), so I am pretty sure I did all the port forwarding correctly. I just rechecked it and everything looked OK. Your explanation of the port forwarding feature in the game options does not clarify it (but just explains normal port forwarding). What I meant to ask is how enabling or disabling this feature affects the network traffic/behaviour of the game. I mean, when one has port forwarding set correctly on their router, they should not need to set anything else in the application settings, right?

In any case, port forwarding (or bad setup thereof) should not interfere at all when we try to play games within our LAN. That is what I find so confusing about this problem.

[bert_the_turtle]

What the game does when the game option Port Forwarding is disabled on the host machine is this: A client that wants to connect to the server does not do so directly (well, it tries to, but will fail if the host is behind a NAT router without port forwarding set up, hence the name of the game option), but sends a request about it to the metaserver. The metaserver then informs the host machine that a client from IP x, port y wants to connect; the host then sends a "you're invited" packet from to that IP and port. That packet will usually open the NAT for incoming packets, and the client is able to connect then. I am assuming (but don't know for certain) that disabling the Port Forwarding game option just prevents the "you're invited" packet from being sent.

In any case, port forwarding (or bad setup thereof) should not interfere at all when we try to play games within our LAN. That is what I find so confusing about this problem.

It shouldn't, you're right. But maybe, on your special router model, setting up a port forwarding rule also affects LAN traffic. I'd try this: disable the port forwarding rules for DEFCON on the router, disable the port forwarding game option (to be able to host games anyway), and then try again to get a LAN game going.

Another thing you may try: do not connect to the LAN server by doubleclicking on it in the list; instead, right click to get the details window, and click on 'connect' there. For some unknown reason, I have to do that to connect to a LAN server here on the university network.

[capnez]

What the game does when the game option Port Forwarding is disabled on the host machine is this: [...]

Ah, thank you very much! That sounds like a pretty nice idea for overcoming networking problems in general (although it most likely has no influence on my problem, it's good to know how it works).

In any case, port forwarding (or bad setup thereof) should not interfere at all when we try to play games within our LAN. That is what I find so confusing about this problem.

It shouldn't, you're right. But maybe, on your special router model, setting up a port forwarding rule also affects LAN traffic. I'd try this: disable the port forwarding rules for DEFCON on the router, disable the port forwarding game option (to be able to host games anyway), and then try again to get a LAN game going.

I think I tried that, but I am not sure. Although it would be strange (and my router would suck for it), it sounds plausible. The problem is that I am not at my family's house any more, so I guess I have to wait a few weeks until I can try again.

Another thing you may try: do not connect to the LAN server by doubleclicking on it in the list; instead, right click to get the details window, and click on 'connect' there. For some unknown reason, I have to do that to connect to a LAN server here on the university network.

Because this is the least explainable, most outlandish suggestion so far, I am sure it will work. Seriously, network games are almost never _not_ a hassle with any game (by the way, SWAT 4 and Warcraft III work fine with no problems at all). :-S And thank you, I will try that the next time I'm there again.