How to Connect a LAN to a Cable Modem

Connecting a cable modem to a local area network is a simple process.

Connecting a LAN to a cable modem allows every computer on the LAN to share the Internet connection supplied by the cable modem. This is done by implementing a router between the local area network (LAN) and the cable modem. This is a straightforward process. The amount of time taken to complete this process will depend on your comfort level dealing with networks, and the amount of computers that will be connected to the cable modem.

Things You'll Need

• Ethernet cables for each device on LAN
• Router

Instructions

1. Obtain IP address information from the Internet provider. You will either be given a range of static IP addresses that can be assigned to the appropriate devices, or they will instruct you to set your devices to obtain IP information automatically.

2. Connect the cable modem to the Internet connection. A coaxial cable will connect to the cable modem, and the other end will connect to the cable connection on the wall.

3. Turn on the cable modem. Some cable modems need to go through configuration when they are first turned on. Turning on the modem at this point will allow it to go through this configuration stage while you are working on other phases of the setup.

4. Configure your router with the settings obtained from Internet provider. In the router configuration, there will be an area to enter WAN settings. You will enter the information given to you by the Internet provider.

   Furthermore, in the router, there will be an area to configure LAN settings. Here you will enter the information for the LAN side of your network. A typical setup is to give the router a LAN address of 192.168.1.1 and a subnet mask of 255.255.255.0.

5. Connect the router to the WAN port of your cable modem. Using an Ethernet cable, you will connect one end of the cable into the Internet port on your router, and the other end will plug into the WAN port of the cable modem.

6. Connect the computers to the router.

   If all of your computers are connected to a switch, then you can connect the switch to the router. This is done by using an Ethernet cable, and connecting one end to the switch and the other to a free port on the router.

   If the router is replacing a switch, then simply move the Ethernet cables from the replaced switch into free ports on the router.

Tips & Warnings

• Sharing a cable Internet connection among many computers can result in slow connections at peak times. If you are in a business environment, you may consider limiting certain applications like video or audio streaming.

References

• "Upgrading and repairing networks‎"; Scott Mueller; 2004
• "Microsoft Windows XP networking and security inside out‎ "; Ed Bott; 2006
• "Network+ Guide to Networks"; Tamara Dean; 2009