.									.									.									/	24
1	1	0	0	0	0	0	0	.	1	0	1	0	1	0	0	0	.	0	0	0	0	0	0	0	0	.	0	0	0	0	0	0	0	1		I.P Address (binary)
1	1	1	1	1	1	1	1	.	1	1	1	1	1	1	1	1	.	1	1	1	1	1	1	1	1	.	0	0	0	0	0	0	0	0		Subnet Mask (binary)
255								.	255								.	255								.	0									Subnet Mask
1	1	0	0	0	0	0	0	.	1	0	1	0	1	0	0	0	.	0	0	0	0	0	0	0	0	.	1	1	1	1	1	1	1	1		Subnet Broadcast (binary)
192								.	168								.	0								.	1									Subnet Broadcast
192								.	168								.	0								.	1									Last Host
⠇									⠇									⠇									⠇									254 hosts possible
192								.	168								.	0								.	1									First Host
192								.	168								.	0								.	1									Network ID
1	1	0	0	0	0	0	0	.	1	0	1	0	1	0	0	0	.	0	0	0	0	0	0	0	0	.	0	0	0	0	0	0	0	0		Network ID (binary)

Use this Interactive Aid to learn about network subnets.

Input the IP of the host in dotted decimal form, and then adjust the slider to set your subnet mask.

As you do, notice the tool converts the IP and Subnet Mask into binary so you can see what's happening.

There are four important results below, shown in green: the Network ID, the First Host (the lowest host IP possible in the selected subnet), the Last Host (the highest host IP possible in the selected subnet), and the subnet's Broadcast IP.

Also, note below that, the binary of the subnet Broadcast IP. This helps in understanding how the Subnet Mask and the Broadcast IP relate to one another.

Finally, note the count of hosts possible on a subnet which uses the selected subnet mask.

When designing a network, you'll want to begin by estimating the number of hosts you expect to be on the same broadcast domain (a broadcast domain is the total of all the computing devices that should be able to communicate with each other without going through a router.)

Suppose you determine you will have no more than a hundred devices. Slide the Subnet Mask slider until the "hosts possible" value is safely above 100. Is 26 enough of a safety margin? After a network design is in place, it is more difficult to change the configuration. And remember: just because you have IP space for 126 computers, doesn't mean you have to use all of it. It's good to have room to expand without having to re-engineer and re-configure everything. Perhaps room for 254 would be ok.

On the other hand, a smaller subnet means fewer possible devices. Each actual device (not each potential device) on the broadcast domain will contribute to the broadcast traffic. Too much broadcast traffic can slow the network down.