How to Add More IPs to a DSL Modem

Expand the capabilities of your Internet connection with a router.

Depending on your ISP, your DSL modem will hand you from one to four IP addresses. Regardless of how many IP addresses your ISP provides you, that is all you get. So you have to take the IP addresses your ISP gives you and use them to give yourself the number you need.

You do this with one or more routers and the Network Address Translation (NAT). In simple terms, NAT takes a public IP, such as the one your ISP hands out, gives out multiple private IPs to you and handles the translation between the two.

Things You'll Need

• Router
• Multiple network cables

Instructions

1. Unplug the power from the DSL modem. Unplug all data cables coming out from the modem. Leave the cable coming in from your phone company in place.

2. Plug one of your network cables into one of the ports labeled LAN on the DSL router. Plug the other end into the WAN port of your new router. The port may be labeled "Internet" or "Incoming."

3. Plug another cable into one of the LAN ports on the router. Plug the other end into your computer. Power up all devices in this order: DSL modem, router, then computer. Allow each to come up before starting the next.

4. Check your IP address on the computer. Instead of the normal IP address you would get from the DSL modem, it will now be something like "192.168.0.1". This is a private address handed out by your router. You can now plug the rest of the cables into the router up to the number of IPs you need.

Tips & Warnings

• Get a router with as many ports as IP addresses that you need.

• Depending on your specific needs, you may get by with a switch, which is cheaper than a router.

• In theory, you could produce up to 255 private addresses using this procedure, but each connection is using and diluting your DSL speed, so it is not unlimited.

• A wireless router will do the same job and add wireless capabilities as well. This adds more IP possibilities beyond the number of physical ports.

• In case of Internet problems, restart the router before calling your DSL company. Many network issues can be solved by a simple reboot.

References

• Computer Technology Documentation: Project: Configuring Your High Speed Internet Using Routers