This article provides detailed answer to the question as to whether you need a router if you have a modem.

router or modem

What does a router do

Technically, a router is a device which is capable of segregating networks and allowing communication between them. For example , a wireless router has two interfaces. One interface connects to the ISP and other interface connects your local area network which is where all users on the home network connect to.

The functionality of the wireless routers is to enable users in the home network to access the internet network provided by the ISP.

Check out wireless routers

What does a modem do

The functionality of a modem is to convert analog to digital signals and vice versa. So for the data in your local area network to reach the ISP network, a modem is required as the digital signals need to be converted into analog before they can reach the ISP. Similarly, signals from the ISP has to be converted from analog to digital, before they reach the local area network.

Do you need a router and a modem

Yes. If you have multiple users on your network you would definitely need a router and a modem as you would have understood that the functionality of a router and modem is entirely different. The router and the modem should be used together to allow users on the network to communicate with the internet.

The router’s job is to enable communication between the networks and that of the modem is to enable conversion of digital to analog signals and vice versa.

Do you need a router if you have only 1 PC

Technically you do not need a router if you have only 1 PC. In this case, the PC can be connected to the modem directly. Most modems have a network card inbuilt in them. They also have basic routing capability. But they do not have features available in routers like wireless routers, inbuilt switches, DHCP, etc. So if you have multiple PCs or systems , a router is needed.

Do routers have inbuilt modem

Some routers have inbuilt modem in them. But ensure that you check with your ISP before purchasing the router since the inbuilt modem on the router may not support the ISP network. Normally the modem is provided by the ISP and the router is purchased additionally or supplied by the ISP.

Check out wireless routers


1. Will modems work with all ISP.

No. Modems are based on the type of connection types used by the ISP like ADSL, DSL, Leased lines, etc.

2. Can modems be configured with IP address

Modems cannot be configured with IP address. IP addresses are configured on routers.

3. How is a typical setup configured with a router and modem

The modem would be connected to the physical port on the wall from the ISP. The modem would be connected to the router using a network cable. The router’s interface connected to the modem would be configured with the appropriate parameters based on the ISP connection type. Options would be static IP, Dynamic IP, PPOE connection, etc.

The username and password combination provided by the ISP is also configured in the appropriate section. If the configuration is successful, the router would receive a public IP address from the ISP which is then used for accessing internet.

4. I have only one PC which is connected to the modem. I want to share the internet connection with three other PCs. What options do I have

Option 1 – The most common method is to use a wireless router and then connect the modem to the router. The PCs can be connected to the inbuilt switch on the wireless router.

Option 2 – The second method is to use a switch. Add an additional network card to the PC connected to the modem. Connect the second network card to the switch. Connect the three PC’s to the switch. Use Windows internet connection sharing feature to share the internet connection with the other users.

Check out switches here

Ask us your Questions – Click here