In the previous lesson, we have learned together what subnetting is and also you found out the basic definitions that are important for this lesson and also for Network Fundamentals Course. In this lesson, we will discuss more subnetting and get through it a little bit deeper.
I would like to start the part two with subnetwork mask and how to apply it. What makes subnet mask unique is that it doesn’t work like IP addresses and also it cannot exist independently. How can subnetwork mask then be used? Subnetwork masks actually accompany IP addresses with a purpose to work together. These great two values can do a lot once they join. What happens if you want to apply the subnet mask to an IP address? It happens that it splits with two addresses into different parts, known as host address and network extended address I have already talked about in the part chapter, chapter one of subnetting. But, I haven’t told what makes a subnetwork mask to be valid. It definitely has to be set to 1. When taking a look at the example, it may look like this:
00000000 00000000 00000000 00000000.
Is it a valid subnetwork mask? No, it is not, because it is set to zero. We told that it has to be set to 1, right? What would be valid then?
11111111 11111111 11111111 1111111 is a valid way.
But, all those zeroes don’t actually represent an invalid subnetwork mask. They can be combined with 1 like we already explained how all the sub-networking need to have two parts.
What about subnetting in practice? It easily works just by applying the correct process of some extended networks addresses. These network addresses need to be applied to an individual computer or even maybe to another network device’s addresses. We know what extended network needs to have, right? It has an address that both includes the network address but also the additional bits which are representing the subnet’s number. With these two elements, you can be sure that you are really supporting so-called two-level addressing scheme. It is actually a standard implementation like one of the IP address.
What about supporting the three-level scheme? Then, we need to have host’s address, network address, and subnet number, and you are ready to go!
All in all, subnetting definitely allows all network administrators to have much flexibility and to experiment when it comes to defining all those relationships within network hosts. But, how can hosts talk on different networks? They can talk only by the so-called specialized network, or even better, through routers or gateway devices. Limiting the access in desirable ways is what can be done with subnetting!
You have learned all that you need about subnetting to get your Network Fundamentals Course done! I hope that you have enjoyed these lessons and that you are willing to get more knowledge because that is exactly what we want to do, to share the knowledge of 21st-century technology with you!