Protocols, Lesson 5: Introduction to subnetting

We explain subnetting as simply as possible.

Subnetting is one of my favorite subjects. It can be as simple as 1, 2, and 3 or as complex as trying to get free tech support from Microsoft.

Subnetting is a very interesting and important topic. I gather that most of you have heard about it or have some idea what it's all about. For those who haven't dealt with subnets before... hang in there because you're not alone!

For some reason a lot of people consider subnetting to be a difficult subject. This is true to some extent, but I must say that I think that most of them see it that way because they do not have a solid foundation in networking. If you read my previous articles in this section, then you DO have a solid foundation.

Some advice
If you started reading about IP on this site from the beginning and have understood everything, then you won't have any problem understanding subnetting. On the other hand, if you do not understand what we have been talking about in the previous pages, you will find this part somewhat difficult. Whichever the case, I'm going to try and explain subnetting as simply as possible and hope to answer all your questions.

Now, because subnetting is a big topic to talk about and analyze in one page, I've split it into a few sections. Logically, as you move on to higher sections, the concepts and material difficulty will increase:

  • Lesson 6: Basic subnetting concepts. This section is to help you understand what a subnet really is. Introduction to the default subnet masks is covered first, and then you get to see and learn how the network is affected by changing the subnet mask. There are plenty of diagrams to ensure that you get the picture right.

  • Lesson 7: Subnet masks and their effect. Here we will look at the default subnet mask in a bit more detail and introduce a few new concepts. Classless and classful IP addresses are covered here and you'll learn how the subnet mask affects them.

  • Lesson 8: The subnet mask bits. Detailed analysis of subnet masks bits. Learn to recognize the number of bits in a subnet mask, followed by an introduction to complex subnets.

  • Lesson 9: Routing and communications between subnets. Understand how routers deal with subnets, how computers which are in different subnets can communicate with each other, and a few general notes on subnetting that you should know.

  • Lesson 10: Subnetting guidelines. Some last information to help you plan your new networks and a few things to keep in mind so you can avoid future problems with subnets.

    Return to the introduction or continue to Lesson 6.

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