Host Behind a Router

Hello all

i am trying to host on my computer an Online Game , but i have router , some people says that server host behind a router is impossible , is that true??
some friend told me it something of the DMZ , well i dont know what to do but i need to host my Online Game behind a router some1 help me plz.

thanks
transporter

 

You have to enable port forwarding. Who makes your router?

 

In your router's setup there should be a setting to place one machine on your LAN "in the DMZ", or similar, meaning that that machine will have nothing blocked between it and the net. It will be for all intents and purposes, just like it was hooked up directly to the modem. Other machines on the LAN will rely on the router to, well... route the web traffic to them, based on requests they make out TO the web. When you make a machine on the LAN a server, the router needs to know where to direct requests to it FROM the web.You do this by "opening a port" or "mapping a port" (in the router) to the LAN machine that's doing the serving.