In this lesson, will talk about the basic knowledge you need to know about subnetting. It will help you a lot to complete your Network Fundamentals Course, and of course, to get more useful information for your IT career.
So, let’s start with the definitions. What is the subnetwork, also known as a subnet? It is the part of IP network, or more precisely, its local subdivision. What would be the subnetting then? It is a process of dividing one network into two or more networks.
When talking about subnetting, it would be the best to understand it as the process of the designation of some high-order bits. These bits need to come from the host and also to be some part of that network. They actually have to adjust the whole subnet mask perfectly. What happens next is that we have a divided network into more networks or smaller subnets.
For best understanding, I will show you on the example how that exactly looks. We will represent a situation where 2 bits are moved from the host part to some other network and to other smaller subnets. They need to have some prefixes. This is how it looks like:
-IP address=11000000.10101000.00000101.10000010 (binary form) with a dot-decimal donation of 192.168.5.130;
-Subnet mask=11111111.11111111.11111111.11000000 (binary form) with a dot-decimal donation of 255.255.255.192;
-Network prefix=11000000.10101000.00000101.10000000 (binary form) with a dot-decimal donation of 192.168.5.128;
-Host part=00000000.00000000.00000000.00000010 (binary form) with a dot-decimal donation of 0.0.0.2.
When talking about computers that are in some way connected with any subnet address, it is important to remember that they have significant and identical groups of IP addresses. What would be the result of that? It is definitely a logical division of the IP address which splits into two exact fields. Those two fields are the host identifier (or sometimes even the rest of the field) and a network number which may also be a routing prefix.
We have already talked about CIDR in previous lessons. CIDR appears again when talking about subnetwork. The routing prefix is most of the times actually expressed as CIDR, Classless Inter-Domain Routing. Of course, it is written in a CIDR notation and it always has the famous slash character you have learned about.
We have also talked about IPv4. When thinking of subnetting and the connection with IPv4, you definitely need to remember that IPv4 can also have some kind of sub-mask or netmask.
What are the benefits of subnetting? When talking about subnetting on some existing network, first, it is a must to know how to allocate addresses properly. What subnetting does is that it can really make a huge difference to enhancing the routing security and network management once the subnetworks are administratively controlled in an efficient way. Subnetting is very popular within large organizations and businesses.
All in all, this would be just the beginning when talking about subnetting. you will learn more about it and all about the characteristics it has in upcoming posts.