Chapter 5 began with a look at IP addressing basics. This included an overview of the binary-decimal conversion process. It continued with an introduction to classful IP addressing, where we outlined how the five classes of addresses are identified, and the number of hosts that each address range supports. The number of available Class A, […]

Recall that classful addresses are decidedly wasteful in the way they allocate addresses –even an entire Class B address range is too large for most companies. To make matters worse, a Class C block is so small that many companies would require many Class C ranges as a viable alternative. On the public Internet, routing […]

By now you’re familiar with the concept of classful addresses, where the default network and host portions of a network address can be easily identified by the value found in the first octet. While the classful system is simple and convenient, the scheme brings about some problems – mainly inefficiently large routing tables, and a […]

We spent time determining the valid ranges of addresses on a given subnet for a reason. Recall from our earlier look at TCP/IP communication that when a host wishes to communicate with another host, it must first determine whether the destination is local (on the same subnet) or remote (on a different subnet). In cases […]

If you’ve been watching closely, you may have noticed the very clear pattern that develops when attempting to determine address ranges. Now that we have the long method out of the way, we can take a look at a quick shortcut. With any given subnet mask value, there is always an associated multiple at which […]

To make things interesting, let’s go through what I consider to be a tough subnetting question. To be honest, if you can follow this question and understand what you’re doing, there isn’t a subnetting question I can ask that you can’t answer. We’re going to go through it step-by-step, just to be sure that you’re […]

Once you’ve managed to define a custom subnet mask that meets your requirements, the next step is calculating the ranges of IP addresses that are valid for a given subnet. Remember that after a custom subnet mask is defined, you have actually turned one big network address space into a number of smaller sub-network address […]

In this section we’re going to look at the process for custom subnetting Class A, B, and C network addresses. The good news is that the process is all just mechanics – if you follow the steps, you will always be able to define a custom subnet mask that meets your requirements.
When defining a custom […]

We’ve already looked at the basic idea of a subnet mask – we know that it is used to define the separation between the network and host portion of an IP address. The next step is looking at how we can define a custom mask to meet the requirements of a particular network. Before we […]

Based on the incredible growth of the Internet, it soon became evident that the IP address space would quickly become exhausted if the growth continued. To account for this, the IETF looked for ways in which the address space currently available could be extended. A future solution exists in the form of IP version 6 […]