What is Subnet Mask and why do I need to change it

What is Subnet Mask?

A Subnet Mask contains four bytes (32 bits) and is often written using the same "dotted-decimal" notation. (For example 255.255.255.0)
Subnet Masks accompany an IP address and the two values work together.

Why do we change a Subnet Mask?

It is a recommended procedure for increasing a DHCP scope when the current scope has entirely consumed the current subnet mask. However, this method requires you to change all subnet hosts and gateways.

When do we change a Subnet Mask?

If you have an address range that has run out of available host addresses, you may be able to change the subnet mask to include a larger share of host addresses. However, simply changing the subnet mask requires that all routers and other statically assigned computers be reconfigured and all DHCP clients have renewed their lease obtaining the new parameters.

The procedure below shows how you can access the Web User Interface to change your Subnet Maskvalue.

Step 1:
To access the Web Graphical User Interface (GUI), click here.

Step 2:
At the Web GUI, click on Setup tab as shown in the following screenshot.

Step 3:
Click on Basic Setup tab as shown in the following screen shot.

Step 4:
At the bottom of the screen, you should be able to see Gateway IP with Local IP Address and Subnet Mask aligned to it.

NOTE:  Class A, Class B, and Class C are the three classes of addresses commonly used on IP networks.
 

Class A, B, and C networks have default masks as shown here:

Class A: 255.0.0.0
Class B: 255.255.0.0
Class C: 255.255.255.0

The default value for the IP Address and Subnet Mask are:

Local IP Address: Default value used: “192.168.1.1
Subnet Mask: Default value used: “255.255.255.0


Step 5:
Once you have changed the values, click Save Settings icon for this changes to take effect.

Was this support article useful?

Additional Support Questions?
Search Again