ip addresses

[bpayne111]

i read a post by mooman_fl which discusses the problem of getting the external ip address of a router (that is not the correct term though... ¿NAT?)

 

from my understanding the post concluded that if a person is behind a router they would never be able to be a host on a game server without using some sort of outside source. (if they used .net to create the app that is)

 

i do not see how this is not possible to do using .net because it would seem to be a common practice.

 

i am making a game server now and being that i don't have my own dedicated server to host such am app. i'd like to allow users to host thier own games if they wanted to. from what i understand this is fine unless the person with a router wants to host a game on the internet instead of at his own network.

 

personally i'm willing to force the user to input the router's local ip address

 

how do i find this ip address on my own anyway? i was asked once by a tech support what it was and i had no idea.. (it's not in ipconfig)

 

there must be a way

brandon

[HJB417]

It is also common practice to use port forwarding on a router.

[bpayne111]

what exactly is port forwarding?

[HJB417]

http://www.homenethelp.com/web/explain/port-forwarding-dmz.asp

 

to find out what the ip is, you need to connect to a sockect outside the the routed/private network and send back to the socket that originated the connection the ip address it used to connect to the listening socket.

[bpayne111]

what is port forwarding?

[HJB417]

an ip can have many ports. the router listens on 1 ip shared by many ccomputers or devices with ips. ip forwarding is when the router forwards an ip packet to one of those computers or devices.

 

So lets say I have a router and 4 machines -> (A, B, C, D). I run a webserver on A on port 80, ftp on B on port 21, a SMTP on C on port 25. Lets say the router's ip is 141.222.2.1.

 

no port fowarding:

 

me connecting to 141.222.2.1:80, 141.222.2.1:21, 141.222.2.1:25 will result in an unsuccessful connection. the router will refuse my connection because the router has no services running on those ports.

 

 

with port forwarding:

1) tell the router to forward/send all requests with a port# of 80 to computer A port 80, send all requests with a port# of 21 to computer B port 21, and all requests with a port# of 25 to computer C port 25.

 

So if 24.68.43.22 wants to connect to the router on port 80, the router will forward this data to computer A.

 

kinda get what I'm saying?

[bpayne111]

yea kinda but it all seems a little wierd

so if i have a user behind a router that wants to host my program, what is required to get the router to allow it to connect to the host computer?

i'm begining to accept that i can't do this with code, so what kind of user input am i gonna need to make it work?

 

thanks

brandon

[HJB417]

a readme file stating what port the server listens on is more than enough.

 

the user will probably know how to do port forwarding.