What is the firewall in computer: Its types and how it works?

What is the firewall:

What is the firewall in computer and why it is used?

If you use internet in your computer or mobile then you must need of Firewall, because without firewall your computer is not secure. A firewall is a security wall that keeps computers away from unauthorized access.

What is the main purpose of firewall?

Firewall is a security system to protect the computer from viruses, it protects the computer from all types of viruses, malware. When the computer connects to any network, there is a possibility of virus coming in the computer, in this situation having a firewall is very important.

Firewall is located at the gateway of the network, it filters the traffic in and out of the network and blocks any suspicious activity if it is detected. Firewall can be hardware or software.

Firewall not only protects your computer from viruses, but if there is a virus in your computer, it also prevents it from going to another computer, thus firewall provides protection from both sides. That’s why it is important to have a firewall in every computer.

The word firewall is used for the prevention of fire. Firewall technology emerged around 1980. When the use of internet started increasing gradually.

What are the categories of firewalls?

• Packet Filter Firewall –

The first paper on firewall technology was published in 1988, when engineers at Digital Equipment Corporation (DEC) developed the filter system. This is known as packet filter firewall. These were very basic types of firewalls which included the features of technical internet. These are called first generation firewalls.

• Stateful Firewall –

In 1990, some colleagues at AT&T Bell Laboratories teamed up to develop the second generation of firewalls. Which is known as Stateful Firewall. These firewalls work like first generation firewalls but they work up to the fourth layer of the OSI model.

• Application Layer Firewall –

Marcus Ranum, Gene Spafford and Bill Cheswick developed the application firewall in 1994 – 95, which is known as the third generation firewall. The major advantage of the third generation firewall is that it can understand certain applications and protocols and block unauthorized data packets from entering the network. This is the most useful firewall.

How many types of firewalls are used?

There are mainly three types of firewalls –

Software Firewall- It is a software installed in your computer, which protects the computer from viruses. such as antivirus. Antivirus is a virus protection system that protects your computer from unauthorized access and harmful viruses. The feature of firewall protection is also available in antivirus. Firewall is already inbuilt even in new generation Operating System like Windows.
If antivirus is not available in your device, then you can buy and install it. Although some antiviruses are also available for free, but premium antiviruses are better for better security. However, software firewalls are no more secure than hardware firewalls, as they can also be hacked.

Hardware Firewall- A hardware firewall is a hardware device that checks incoming and outgoing traffic and blocks suspicious activity. Nowadays hardware firewall is already present in all routers. Firewall starts working in all the computers that are connected to a router.

When some work is done on the Internet by the computer, the firewall protects the computer from viruses and malware. Hardware firewalls are more secure than software firewalls. They protect every device connected to the network from viruses.

Proxy Firewall- Proxy firewalls are considered the most secure firewalls. These firewalls keep an eye on the traffic coming from the Internet Protocol network. Proxy firewall has its own IP address.

When the proxy firewall receives a request for an Internet resource, it first finds the data packet in its local cache, if it finds the packet in its local cache, it sends the data packet directly to the user without sending a request to the Internet user.

But if he does not find the data packet in his local cache, then he uses his own IP to request the data from the server on the Internet, and when the request comes to the proxy server, it sends the data to the user. gives.

How Does Firewall Work:

The firewall already has network security rules, based on which the main work of the firewall is done. These rules are set by the Network Administrator as per the requirement of the network.
The parameters on which a firewall will filter incoming data packets in the network are determined by the rules set within it.

When a data packet arrives on the network, the firewall examines the data packet at the gateway, if the data packet is contrary to the rules set in the firewall, then the firewall blocks it from entering the network, due to which only that packet is allowed through the network. Can enter into which is safe.

Similarly, when a computer wants to send any data in the network, the firewall first checks that data packet and sends only secure data to the network. In this way the firewall acts as a wall. Firewall acts as Two Way Protection in a network which provides more security to the devices connected to the network.

Advantage of Firewall-

Following are some of the major benefits of firewall,

• Firewalls monitor incoming and outgoing traffic on a computer, and examine each data packet. If they contain any kind of suspicious or dangerous information that can harm the computer, then stop it.
• Firewalls block Trojans. These are viruses that stick with computer files and cause more damage at the destination. Trojans are more dangerous because their presence in the computer is not realized until some strange activity starts in the computer.
• Firewalls protect your computer from hackers. Firewalls prevent hackers from accessing your network.
• Various remote users can be added to a LAN network, taking advantage of this, hackers can access the network or computer through remote access. Firewall prevents all these unauthorized remote access from entering the computer or network.
• You can manage Bandwidth through Firewall. Since we do not have unlimited bandwidth, it is necessary to control the bandwidth available to us.

Disadvantage of Firewall –

Along with the advantages of firewalls, there are also some disadvantages. Some of the disadvantages or drawbacks of firewalls are as follows –

• Hardware firewalls are more expensive because they are more secure. The security and maintenance of hardware firewall is also expensive.
• Maintenance of firewall is easy for a small network or company, but a separate staff is required to maintain the firewall in large networks or large organizations.
• Firewall does not have the ability to stop some hi-tech viruses and malware. Such viruses look safe to see but they are actually harmful to the computer.
• A software firewall protects only the computer it is installed on.

Firewall FAQ:-

Explain what is firewall?
A firewall is a network security system that prevents viruses and malware from entering a network.

How many types of firewall are there?
There are mainly three types of firewalls – software firewalls, hardware firewalls and proxy firewalls.

What is the main function of firewall?
The main function of a firewall is to filter data packets coming into a network and prevent unauthorized data packets from entering the network.