And continuing our tutorial on the TCP / IP protocol, let’s talk about another protocol that makes up the TCP / IP, the IP. If you want to see part 1, click here.
It the acronym for Internet Protocol. This protocol defines that any device connected to a network must have a unique address. This address is called IP address.
The most common IP address on the Internet’s still the version 4, also known as IPv4. In this case, a 32-bit number is divided into 4 parts, each containing 256 different combinations (0 to 255). Therefore, we’ve 4,294,967,296 different combinations of 0.0.0.0 to 255.255.255.255. That generally speaking, ‘cause we can’t use the extremes of this range of numbers.
Types of IP addresses
IP addresses can be used to identify a single device (such as computer, printer, video game, smartphone, etc.) but also to identify the network in question.
See the following example: If you are with the address 192.168.0.4 on your computer, with a subnet masks 255.255.255.0, that means:
- Your computer’s address is 192.168.0.4;
- Your localhost address is 127.0.0.1;
- Your network is a C Class and have the number 192.168.0.0;
- The broadcast address from your network is 192.168.0.255.
Now we’ll see how we arrived at these conclusions.
It’s the address that reaches all network devices (also called nodes). By default, the latest issue of Network (X.X.X.255) intended for sending in broadcast, in other words, for all network nodes. In turn, the first number (x.x.x.0) serves only to identify the network address.
It’s the number used so that the device can be identified. This will range from 127.0.0.0 to 127.255.255.255. By default it uses the number 127.0.0.1 as localhost.
IPv4 addresses can be categorized from A to E. Here’s how:
- A Class: from 126.96.36.199 to 188.8.131.52;
- Localhost: from 127.0.0.0 to 127.255.255.255;
- B Class: from 184.108.40.206 to 220.127.116.11;
- C Class: from 192.0.0.0 to 18.104.22.168;
- D Class: from 22.214.171.124 to 126.96.36.199;
- E Class: from 240.0.0.0 to 255.255.255.255.
Currently, mainly we used the classes A, B and C. We’ll see in the future details about classification of IPs and why they are used.
The mask defines how many characters will be available to fill each composition of IP address. For example, we know that the number of limit used in each division of the IP address is 256 (0-255). So if the mask contains the number 255 in that octet, we can’t carry change this number ‘cause we’ve 0 (zero) combinations available for exchange. See:
- IP address: 10.0.0.3;
- Mask: 255.0.0.0.
In this case, we can change all the numbers except the 10, because the subnet mask prevents us to do changes in the first issue.
This can be seen when you need to change the IP of your device manually or when you want to consult a folder in a computer in another network. The mask prevents you check, for example, computer files that are in the 188.8.131.52 network.
TO BE CONTINUED…
Next post, we’ll continue talking about it. Do not lose!
Author: Esdras Nunes
Rede LAN Soluções em Informática.