How to Use Two NIC Cards in One Computer

By Mikhail Polenin

Installing two network interfaces in one computer is not uncommon, but the process after the installation usually baffles the average computer user who wants to share the computer's connection to the Internet with other computers. You can go two ways when sharing your Internet connection to other computers in your network, while having your computer act as the host gateway for the other computers. Both methods are relatively easy and can be done by anyone with a good command of the Windows interface.

Bridging Your Internet Connections

Step 1

Go to your Control Panel from the Start menu.

Step 2

Navigate to Network Connections.

Step 3

Click on the first NIC that you want to bridge.

Step 4

Hold down the CTRL key while clicking on the second NIC that you want to bridge.

Step 5

Right-click on one of the selected NICs and click "Bridge Connections."

Enabling Internet Connection Sharing (ICS)

Step 1

Go to your Control Panel from the Start menu.

Step 2

Navigate to Network Connections.

Step 3

Right-click on the connection belonging to the NIC that is connected to the modem or directly connected to the Internet.

Step 4

Click Properties.

Step 5

Click the "Advanced" tab.

Step 6

Click the option that allows other computers to connect via your computer's Internet connection. It is under "Internet Connection Sharing."

Step 7

Click OK.

Step 8

Click "Yes" if a message appears asking if you really would like to enable Internet Connection Sharing.

Tips & Warnings

  • For the average Internet user, it is all about preference when choosing whether to bridge connections or enable ICS. Bridging is exactly as the name implies. It makes your computer into a network bridge that is managed by your operating system. ICS basically enables other computers connected through the second NIC to use your Internet connection on your first NIC (the one connected to the Internet).
  • It is not recommended for the average computer user to use either of these methods to share an Internet connection. You are usually better off with configuring a router to work side-by-side with your modem. The reason for the suggestion against using two NICs is because both methods require your computer to be on for others to connect to the Internet. You should only do this if you plan to keep the computer on continuously or do not mind preventing the other computers in your network from accessing the Internet while the main computer is off.The more computers you have connected to an unsecured network, the more vulnerabilities you are exposing. You should always have a hardware or software firewall running on your computer aside from the basic operating system firewall. The most recommended type of firewall is one that prevents Denial of Service (DoS) attacks and port scans against your computer. Hackers can easily infiltrate networks that are not behind an NAT (Network Address Translation) service.