.
.

Calculation AND operation in VLSM

How a computer knows the network concerned and which route should send packets
I said that every computer in an IT network (either LAN, WAN or Internet) has an IP address and mask.

These basic data are sufficient to determine that the computer network is concerned. Here I would also noted one of the devices is important for the functioning of large LAN or Internet network.
This the device is called 'Router'. The router is actually a small computer that has similar features as the PC desktop or Laptop (Notebook) computer. But the router is a story unto itself, and it serves us to forward packets sent by one computer from one location to another computer in another location in a network. How to Router know where to forward each packet, the Router is important to know the IP address and network mask. Using these two parameters Router know where to forward the particular package.

What it actually works Router to know where to forward the packet. The Router performs AND-ing between IP addresses and masks.

What is AND-ing?

The router (computer) uses Boolean 'AND' operator's when performing AND-ing, Boolean operators AND, OR and NOT.
I will not explain everything, but only briefly remind you of the AND operator.

How Boolean operator 'AND' work?
AND operator, I can translate the layperson as "one and the other".
So I would say just if you match two characters, the result is The character (in this case binary digit). Or simply put both of them must be the same. Please see Figure5

Figure 5.

AND-ing operations or calculation in IT Networks

Or simpler

1 and 1 = 1 (1 and 1 = 1)
1 and 0 = 0 (1 and 0 = 0)
0 and 1 = 0 (0 and 1 = 0)
0 and 0 = 0 (0 and 0 = 0)

Let's go to the next page tutorial.