# Calculating IPv4 Provided an IP address and a Subnet Mask, we can use binary conversion to find the Network Address, total usable IP addresses and range and the the Broadcast Address.

A Network Address looks like this or something similar : 192.168.1.0/24

The CIDR tells us how many binary digits are turned on in the subnet mask. /24 tells us we have 24 bits “on”(1). In this case the 24 first digits are 1 which gives 11111111.11111111.11111111.00000000 or 255.255.255.0

Just by looking at the CIDR we know that the Subnet Mask is 255.255.255.0. You can refer to this page for more info on CIDR.

We can find the CIDR by counting the number of bits are are turned on.

Let’s find more about the Subnet Mask and it’s purpose.

Let’s use 192.168.25.55 as our given IP. What would be the Network Address? We can tell the network address will be 192.168.0.0 as the Subnet Mask is 255.255.224.0. This means on our network, only the two last octet will change.

Next using AND equation(0 + 0 = 0, 0 + 1 = 0, 1 + 0 = 0, 1 + 1 = 1) we can figure what will be our network address 3rd octet.