Valid subnet address: To figure out the valid subnet address, simply subtract the subnet mask from 256. For example, if you had a Class A mask of 255.240.0.0, the equation would be 256-240=16.

Devices also have a subnet mask, which defines which part of the IP address belongs to the network and which part belongs to the device. The gateway, also called a default gateway, is the device ...

How to Calculate Subnets With Microsoft Excel. IP addresses on your company network consist of three parts: the network address, the host address and the subnet mask. The network address ...

I have an Excel spreadsheet containing IP addresses and subnet masks. I need to derive the subnet of each IP address in the spreadsheet.Example: IP (column A): 10.1.230.84, Subnet Mask (column B ...