IP Address Classes|Types

ip address classes

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Now as we have already seen what is an IP address, let us see some of its terminologies. By the end of this article, you will get to know the IP address classes and types.

Let us start with the types of IP address first.

Types of IP Address

Static IP Address

This type of IP address is assigned manually by the network administrator. While it is cost effective, but is less secure. It is mostly used for FTP servers or where security is less concerned.

Dynamic IP Address

As the name suggests, this type of IP address is assigned dynamically every time. It is assigned using Dynamic Host Control Protocol (DHCP). It is costlier to implement than static but is more efficient in terms of security.

This is used where security is more concerned.

Public and Private IP Address

Public IP Address

Almost all the IP addresses are public addresses apart from a range of few. The IP address you use to connect to the Internet is your public IP Address. While what you saw in previous article was private IP address.

You can see your public IP address just by searching my public IP address on search engine.

Private IP Address

Due to the limited number of host IDs available to assign, the concept of private IP address came in picture.

There was also wastage of IP addresses as suppose if a company gets some IP addresses in some range 9.x then it won’t require all of them and those will get wasted.

Now the private addresses can be used locally any where and same IP address can be assigned to more than one device provided that they are in different network.

So, how private IP addresses being same for two devices (in different network of course!) connect to the internet? Well, by using their public IP address which the NAT (Network Address Translation) converts private to public address. (We’re going to see it later in details.)

Ranges of Private IP Address

  • 10.0.0.0 – 10.255.255.255
  • 172.16.0.0 – 172.31.255.255
  • 192.168.0.0 – 192.168.255.255

Classes of IP Address

IP address is divided in 5 classes. Class A, B, C, D, E. While classes A, B, and C are used, classes D and E are reserved.

Classes are as follows:

  • A: 1.0.0.0 – 127.255.255.255
  • B: 128.0.0.0 – 191.255.255.255
  • C: 192.0.0.0 – 223.255.255.255
  • D: 224.0.0.0 – 239.255.255.255 – Multicast range
  • E: 240.0.0.0 – 254.255.255.255 – Research

As you can see, the first octet values are important in understanding IP address classes.

Every class has a default subnet mask. Which means, the network part and host part. for class A, hosts bits are 8, for B 16, and for C 24. This means 129.0.0.3 and 129.0.1.5 are in the same network but 129.1.1.1 is not.

Classful IP addressing wastes many IP addresses. To overcome this, we use classless inter-domain routing. We will see this in details in the next article.

Now we will see some special IP addresses.

  • 0.0.0.0/8 Addresses for communicating with the local network
  • 127.0.0.0/8 Loopback Addresses
  • 169.254.0.0/16 Link Local Address

That’s it from this article. You might love to read other posts in Networking.

As you are here, you might want to watch the networking how to video.