When Hosting a game... Do you have to enter your external IP? [Archive]

View Full Version : When Hosting a game... Do you have to enter your external IP?

Worms-Net

12 Sep 2006, 22:30

I mean... for all of you that can host games on worms... do you have to enter your external ip and force it? just enter it not forcing it? never heard of it?
Can everyone here that host games on worms armageddon tell me how you manage to host games... My problem is that I thought...that by entering my internal IP in the case box...my router will just route it to me using port forwarding, however I notice the only way for me to host is forcing my external IP... does it happen to you?

M3ntal

13 Sep 2006, 01:12

Worms-Net

14 Sep 2006, 00:38

There's a guide to hosting W:A games on http://www.nanacide.com/wahelp.

For a full explanation of the networking behind W:A, including the reason why you have to force your external ip, check this post: http://forum.team17.co.uk/showpost.php?p=524054&postcount=17

I study network administration... I read the document but I still don't get why worms have to be told...hey this is my public ip address... shouldn't the packets; when they are sent to the router (for hosting) reencapsulate (as always)... and change my private ip into a public one so when they click the room my external ip shows....? or is that information in the data field? is it what worms uses? I'm not an expert but I just don't get why...

franpa

14 Sep 2006, 04:27

if you use dial up and not use a router then you dont force it... however if you have broad band and/or a router then yes you do... you do for broadband because theres not much point in not cause your IP should be static... and routers tend to change what programs detect your wan IP address is.

M3ntal

14 Sep 2006, 09:39

I study network administration... I read the document but I still don't get why worms have to be told...hey this is my public ip address... shouldn't the packets; when they are sent to the router (for hosting) reencapsulate (as always)... and change my private ip into a public one so when they click the room my external ip shows....? or is that information in the data field? is it what worms uses? I'm not an expert but I just don't get why...
This is a best guess, i don't know exactly why, as HTTP servers are able to get your routers IP fine:

Your PC sends your IP to WormNET on port 80, in a packet data field. In other similar situations (other games, programs, etc), it could be any port that your PC uses to send this data. There is no way for the router to tell what packets it should alter, as this IP could be in any arbitrary format.

The only way to solve this would be to alter the header of all packets on any port from your PC to contain the routers IP as the source address, which brings up another problem; the only traffic you would receive would be that which is sent to the port(s) you have forwarded, because the returned packets would contain the router's IP instead of your PC's as the destination address, and the router would just drop them thinking they are intended for itself.

Needless to say, forwarding all ports to your PC would undermine the concept of a firewall and stop any other PC's on the network being able to receive data.

Worms-Net

14 Sep 2006, 18:57

The only way to solve this would be to alter the header of all packets on any port from your PC to contain the routers IP as the source address, which brings up another problem; the only traffic you would receive would be that which is sent to the port(s) you have forwarded, because the returned packets would contain the router's IP instead of your PC's as the destination address, and the router would just drop them thinking they are intended for itself.

Needless to say, forwarding all ports to your PC would undermine the concept of a firewall and stop any other PC's on the network being able to receive data.
Dude the packets coming from the internet to my pc contain the router IP anyway... the reason the router doesn't drop them is because it knows it was me that sent it so it fowards it to me as replies so no port forwarding needed. something can be done... TEAM17 release new patch please.

M3ntal

16 Sep 2006, 00:37

Oh, fair enough. I always thought the source and destination fields stayed the same and the MAC address changed between hops.

CyberShadow

16 Sep 2006, 01:56

Hi,

I agree that it's pretty silly that you have to enter your own IP address in order to host, while the server can automatically detect it. But this is how the game works, at the moment.

W:A will switch to a new network protocol when W:A and WWP will be merged. There won't be a need for such nuisances by then.
That'll probably be around Q1 2007 though.

KRD

16 Sep 2006, 13:36

Q1 2007

No dates! Don't break the tradition, heh.