What Is A Firewall And Why Is It Called A Firewall? How Does Firewall Work, And How Many Types Are There?

If we want to speak in simple language, we must say that after the switch in all kinds of network equipment, we can introduce the word firewall as one of the most used words in the field of computers and networks.

Many times we hear these familiar sentences from Inver and Honor: change it, get a firewall for the network, add a specific role to the firewall, turn off your firewall, and… today, in this article, we want to do it in the simplest possible way.

And, of course, let’s talk about the firewall and garlic to the onion of this software or hardware by expressing my own experiences. Stay with us until the end of the article.

What is a firewall, and why is it called a firewall? How does a firewall work, and how many types are there? If we want to speak in simple language, we must say that after the switch in all kinds of network equipment, we can introduce the word firewall as one of the most used words in the field of computers and networks.

Many times we hear these familiar sentences from Inver and Honor: change the firewall, get a firewall for the network, add a specific role to the firewall, turn off your firewall, and… today, in this article, we want to do it in the simplest possible way.

And, of course, let’s talk about the firewall and garlic to the onion of this software or hardware by expressing my own experiences. Stay with us until the end of the article.

A little about the history of firewalls and generations of firewalls

In the beginning, there was no such thing as a firewall in computer networks. After the emergence of routers or network routers, the need was felt that we should be able to limit traffic in some situations. In this situation, something called Access Rule or ACL was introduced in routers, which are the basis of many firewalls today. The access rules define which addresses can go from where to where or not.

What is the first generation of firewalls? Added antivirus

This was the first generation of firewalls that prevented the entry and exit of malware, such as computer viruses and malware threats. This generation of firewalls is also known as Generation 1 Virus. The firewalls that worked before the first generation of firewalls only worked as packet filtering or packet filtering. These types of firewalls revolutionized the cybersecurity industry, and the first generation of firewalls was introduced to the market in the late 1980s.

What is the second generation of firewalls? Prevent cyber attacks

This generation of firewalls is also known as Generation 2 Networks. These types of firewalls were introduced in the mid-1990s. They were introduced to the market with the expansion of communications and the Internet and, as a result, the development of network attacks and Internet attacks. became

What is the third generation of firewalls? Prevention of software threats and intrusion detection

In the third generation of firewalls, this time, the targets of attacks by hackers and malware writers were applications or programs. According to the same type of threats, mechanisms to prevent attacks on applications or software were also added to firewalls. These firewalls were introduced to the market in the early 2000s and introduced the tools of Intrusion Detection Systems or IDS. This generation of firewalls is also known as Generation 3 Applications.

What is the fourth generation of firewalls? Prevent robotic attacks

This generation of firewalls is also known as Generation 4 Payload. Attacks are becoming more advanced daily; in 2010, the fourth-generation firewalls were designed to focus on countering robotic attacks (zombies, etc.), multipurpose, purposeful, unknown, and scary episodes, and they were increasing. Anti-bot products were added to firewalls from this generation.

How many types of firewalls are there?

One of the most challenging classifications in the discussion of firewalls is the classification of firewall types. On Iranian websites, you can see various sorts of firewalls. Still, as a cyber security expert and white hat hacker, I have a more exciting variety of firewalls that I will present to you below:

Types of firewalls based on OSI layers

If you are familiar with network or OSI layers, it will be easier to understand how firewalls work. Firewalls can be divided according to OSI layers. From the second layer, where information is in frame format, and there is no IP IP concept, we have Transparent Firewalls.

In the third layer, which is based on the IP mechanism, we have Packet Filtering firewalls, and in the same way, the firewalls of each layer are different. The higher the layer of firewalls, the more complex the threats and the stronger the firewall should be; seventh-layer firewalls are also known as Web Application Firewalls or WAFs.

Types of firewalls based on hardware and software

In reality, we don’t have a hardware firewall in the security world in the world of security. All firewalls are software; if you see something called a hardware firewall, it is installing firewall software on a computer as a server. All firewalls are software; if you see something called a hardware firewall, it is installing firewall software on a computer as a server. But what has become common in the market is that any firewall that is in the shape of a router and switch and the color of its box is red is stronger!!

For example, we have Cryo if the hardware in the market is precisely the same as the Cryo Control firewall software installed on a ready-made computer box. For more information, refer to the article on the difference between a software firewall and a hardware firewall by Engineer Nasiri.

Firewalls based on size and performance level

Suppose that you have an operating system, a network in the dimensions of a home, a network in the size of a small company, a network in the height of a large company, a network in the dimensions of a small organization, a network in the dimensions of a large organization and finally a network At the level of a province or even a country. The question is whether the management and monitoring of the traffic and threats of these networks are the same.

Of course not. The network firewall equipment is also variable based on the dimensions and sizes of the network and the incoming and outgoing traffic of a network. For example, you use a free firewall in Windows for your operating system. Still, to manage the Internet traffic of a country the size of Iran, you will need firewall equipment such as the F5 firewall with billions of costs. Therefore, we divide the firewalls into dimensions, sizes, and performance levels.