   Unable to connect through a router
  I have a server and client program,using winsock. And im behing a router. When im running both of them on one machine and i use my local ip im able to connect, but when i try to use my internet ip i cant connect. I thought that maybe ill have to use combination of my local and internet ip in the client program, but i dont exactly know what to do.Thanx 
  Routers provide private IP''s to computers connected to it. That''s how it''s able to use one external IP for everyone and still be able to distinguish computers connected to it. The private IP are usually 192.168.x.x or 10.35.x.x (use ipconfig.exe to figure it out). These IP addresses are only valid behind that router.What you need to do is use your browser to connect to your router (they have a built-in HTTP server). Usually this is at 192.168.2.1 but it may vary (it''s the "default gateway" as reported by ipconfig). When you find it, login and look for a port forwarding, virtual server or other similar section. You''ll know you found it when it has entries for public/private ports and IP to forward to. What you need to do is tell your router to forward incoming packets on those ports to your computer''s private IP address (it rejects them by default which is why people can''t connect to you). ;  Thanx a lot, i just have one more question. How can i do that by a program ? ;  You can''t. ;  It''s router specific, you just tell your users to forward port N if behind NAT and make them figure it out.   --Dustin ;  http://www.mindcontrol.org/~hplus/nat-punch.html 