What is a DMZ & how to make some router configurations?

The Internet is usually referred to as an unsecure network, when it comes to network security. In this regard, local area networks are more preferred as they can be easily managed and kept secure. At times, you can’t help but hook up your Local Network to the Internet, to enhance accessibility and improve productivity. It exposes the servers and the resources to exploiters.

When talking about keeping our network and resources from prying eyes, a DMZ is created to keep the resources safe, but what exactly is a DMZ? Let’s take a look:

What is a DMZ?

A DMZ or a DeMilitarized Zone is a logical sub-network which separates the local area network from the untrusted network (in most cases, the Internet). The required services and resources, such as external facing servers, are placed inside the DMZ. This allows the organization to employ these whenever needed, keeping the LAN away from unauthorized access. This adds an extra layer of security to the Local Area Network, as it restricts anyone from directly accessing the data and the servers through the Internet.

While Implementing a Demilitarized zone, a firewall plays a significant role. It ensures that apt policies are in place to protect the local network and the resources, and that they are separate from the DMZ. It does all that while ensuring accessibility of the DMZ.

Remember, it is a bad idea to start implementing a DMZ yourself unless you are firmly familiar with networking methods and techniques. Although it isn’t usually required but is generally encouraged by security conscious organizations.

Let’s explore how to configure a DMZ host.

DMZ Host Configuration

Step – 1

Open up your router management page and login to it.

  • Open up your web browser.
  • Type the address of your router/modem into it. It’s usually one of these:

If it isn’t any of these, try contacting your ISP to find it out.

  • On the login page, you’ll be asked for a username and password. Defaults are usually admin and Then login into the admin dashboard.

Step – 2

For 3G & Wireless Routers

On the dashboard. Lookup the Forwarding button and then click “DMZ” located at the left. Then go ahead and:

  • Check “enable” by the “current status”.
  • Enter the IP address of the computer which will be used as the DMZ Host, into the Host IP address box and then click save.
  • Now go into the system tools and reboot your device.

For ADSL modem/routers

Select the “Advanced Setup” option and then select “NAT” and finally select the “DMZ Host”. Here:

  • If you want to activate you DMZ host, enter the IP of the PC which will be used as the Host.
  • Save it and then apply.
  • Go to “Management” and reboot your device.


You have to be very careful when planning a DMZ. If you are unsure about anything, make sure that you consult a professional right away and prevent yourself from messing up your configuration for good.