I am trying to get help with home networking and private IPs. I have a DSL modem that uses DHCP and it assigns my first computer with the IP address of 192.168.1.1. What I need to do is to beable to access a certain private IP (the 192.168.1.1) directly from the internet. Is there a certain port that has to be used or do I need a router to go with the DSL modem? If I go to a website that tells you your IP, it gives me the IP assigned by the ISP. Is there a way to use that IP to access the first computer on my network, which is 192.168.1.1. I actually have a program that uses this, and right now if I use the IP from the ISP, it does not respond because I'm guessing it doesnt know where to go once it reaches the modem which obviously has the IP given by the ISP. Any help would be great or maybe if someone knows a website that could help me do this. Thanks.

Is the 192.168.1.1 being assigned by a router?

If so you need to port forward the correct ports the the internal PC's IP.

The best way would be ,if your router supported PPTP or IPsec...

The DSL modem is assigning the 192.168.1.1. All I want to be able to do is to access the computer from the internet or in other words, another computer. The ISP IP address is another IP which is the IP that will need to be used, but how do I set it up to go from the IP address given by the ISP to the 192.168.1.1 address assigned by the modem. Basically I have a LAN setup for the DSL router. The first is the Modem IP address, which is 192.168.1.254, then it wants the subnet mask which is 255.255.255.0, then it has a DHCP start number, which is 192.168.1.1 and an end number. I dont see where I can pick which port each is on. I have another screen on the modem setup that tells me my actual IP address, which is 68.xxx.xxx.xxx. This is the IP a website tells me I have also. So I guess I would have to use that IP address to access a computer connected to the DSL router on the network from another computer on the internet. How would I do this cause I cannot find any setup on my DSL modem to do this. IT is a Westell Wirespeed. Thanks for any help.

okay I just found a sevices section on the modem webbased setup. There are a bunch of "well-known" options for it. Like FTP, PTPP and IPSEC ESP and IPSEC IKE. I setup a PTPP I think and it said local port is 1723 and global port is 1723 then it says local IP address is 192.168.1.1. Now what do I do with that port number? Do I use the ISP provided IP address which is 68.xx.xx.xx with that port and if so how? Thanks.

Does it allow you to pick a port not in the "well-known" options? If so, you need to figure out which port is used when using whatever you want to access the computer with (some games use certain ports, so you would have to add those ports to that services tab as global and local, and select 192.168.1.1 as the local IP to accept that port). You have to do this for all ports that your program or whatever uses.

Okay, it does let you do a custom port forwarding. Let me try to find out what port the program I have is using so I can forward that port. I will see if that works.

I cannot seem to get it to work. Is there a way to test to see if it is going through to the computer? And do I use the ISP issued IP address and then specify the port I picked to let it pass through?