How To Configure A Laptop As A Wireless Internet Access Point

Note: I am making the assumption that you already have a basic understanding of IP routing as well as how to use the Windows registry editor. You will also need to install and configure a proxy package, such as winproxy (I actually used an older version that performs Network Address Translation using the VZAccess Valid Internet IP assigned by Verizon as the hiding address). This allows the computers on your internal network to access the Internet. Optionally, you could install Windows 2000 Prof / Server which can perform Internet connection sharing.

I have a relatively new HP/Compaq laptop running Windows XP SP2. I ordered the VZAccess card (aprox $149) and the monthly services (aprox $59.99) from Verizon . The VZAccess card installs in the PCMCIA slot and the laptop already has an integrated 10/100/1000 Ethernet controller. This effectively gives me two Ethernet cards. All routing devices, in this case my laptop, must have at least two Ethernet cards to route between networks, in this case, my home office network and the Internet.

The internal network card, the real Ethernet port integrated into my laptop, was assigned an address such as 192.168.0.254/24 (to be my default gateway for all my internal computers) and the VZAccess card is dynamically assigned an IP address from the carrier.

The real trick is what needs to be done to make WinXP Prof act as a router. In order to do this, you must make a registry change. For those of you with little experience in making registry changes, I must tell you that if you make a serious mistake, you run the chance of really messing your system up. There are Proxy packages that can take care of this for you, and do not require this routing change.

Configuring Windows XP Professional To Route IP

In order to make Windows XP Prof performing IP routing between network segments, you need to perform some changes to the Windows Registry.

 At the Start -> Run command, type regedit and press enter. Then navigate to the following "HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesTcpipParamet ers". Selected the "IPEnableRouter" entry, which by default will have the value 0, and change it to 1. Close the registry editor, and reboot your system.

When the system reboots, it will be able to route traffic between your internal network and the Internet (Your Wireless card). Of course, you need to adjust your DNS information to point to an appropriate Domain Name Server on the Internet. All of your internal workstations / systems must point to the internal network card / IP on the laptop as the default gateway.

Below is a small / basic diagram of this setup:

Conclusion

This seems like a pretty easy setup, and it can be if you have a good understanding of routing and network address translation. The goal of this article was to demonstrate that you can configure a pretty inexpensive solution that can keep you connected in the event of a communications / power failure. Of course, there are other things to consider, for instance, we were without power for 7 days, however, we had a gas generator that kept us going. The bottom line is, where there is a will, there is a way. And the way for me was the Poor Mans Wireless Internet!