how to access a computer with TCP/IP threw another network.?

Answer 1

This depends on if the computer you are accessing is behind a firewall and or NAT router. Most connections are behind a NAT or Firewall, so you'll need to check. If you're not, you should be able to access it by typing the IP address of the host on the other end. Otherwise, being behind the firewall or NAT router, you can still access the host using the IP address given by the ISP, but you'll need to configure the router or firewall to forward these requests to the host. This can be done by either placing the host in the DMZ or forward IPs or port requests to a particular IP behind the router or firewall. Placing the computer in the DMZ usually is the easiest to configure, but most dangerous because it would effectively be opening the computer to the Internet without the protection of the firewall . The recommended and sometimes more time consuming method is to create an access rule in the router or firewall that forwards needed ports and IPs to the host behind the firewall or router. Sadly, either situation you'll need to refer to the firewall or router manufacturer for guidance on how to do this