What Is Firewall? | 5 Advantages & Disadvantages

Today we will tell you about the firewall. What is Firewall, Learn about how it works and its advantages and disadvantages

What is firewall

What is firewall

A firewall, seen from a network security perspective, is a device that monitors future incoming and outgoing network traffic and allows or blocks data packages based on a set of security rules.

Its purpose is to create a barrier between your internal network and external sources (such as the Internet) to block bad traffic such as viruses and hackers.

How does a firewall work?

Firewalls carefully analyze incoming traffic based on pre-established rules and filter traffic that comes from insecure or suspicious sources to prevent attacks.

A firewall protects traffic at computer entry points, called ports, where information is exchanged for external devices. For example, “The source address in port 22 is allowed to receive”

Think of the IP address as a house and the port number as a room in the room. Only people who can be trusted (source) are allowed to enter the house (destination address).

This is then further filtered so that people in the house can only access certain rooms (destination port) Access is allowed, depending on whether they are the owner or not, a child, or a guest.

The owner allows any number of rooms (any port), while children and guests are allowed to enter a particular room set (specific port).

Types of firewalls

Firewalls can be both software and hardware, although it is best to have both.

Firewalls in the form of software are programmed on each computer and control traffic through port numbers and applications, whereas a physical firewall is a piece of equipment installed between your network and a gateway.

Package Filtering Firewall, the most common type of firewall, examines packages and prevents them from passing if they do not match a set of established security rules.

This type of firewall checks the source and destination IP addresses. If the package matches the “allowed” rules on the firewall, it can be trusted to enter the network.

Package filtering firewalls are divided into two categories:-  

  • Stateful
  • Stateless

Stateless Firewalls without a citizenship check packages independently of each other and have no context, making them an easy target for hackers.

In contrast, a stateful firewall that can be maintained considering the information about the packages passed in is considered secure.

While packet filtering firewalls can be effective, they ultimately provide very basic protection and a very limited one.

Examples may be, that they cannot determine whether the on-demand content sent to it in those applications will negatively affect it or not.

If an evil request is allowed from a trusted source address it will produce, such as deleting a database, a firewall will have no way of detecting it. Next-generation firewalls and a proxy firewall are more equipped for threat detection.

Next-Generation Firewall (NGFW) combines traditional firewall technology with additional functions, such as encrypted traffic monitoring, intrusion prevention systems, anti-virus, and more. Notably, it has a deep package inspection (DPI).

Whereas the basic firewall only looks at package headers, a deep package checks the data in the package itself, allowing users to be more effective in identifying, classifying, or preventing packages with dangerous data. Learn about NGFW ForcePoint here.

Proxy firewall filtering network traffic at the application level. Unlike a basic firewall, a proxy acts as an intermediary between the two end systems.

The client must send a request to the firewall, where it is prepared for a series of security rules and then allowed or blocked.

Specifically, Firewall Proxy monitors traffic for Layer 7 protocols such as HTTP and FTP and uses static and in-depth package inspection to detect harmful traffic.

Network Addressing Translation (NAT) Firewalls allow multiple devices with independent network addresses to connect to the Internet using the same IP address, hiding individual IP addresses.

As a result, attackers scanning the network for IP addresses cannot capture specific details, leading to greater protection against attacks.

NAT firewalls are similar to proxy firewalls, where they act as an intermediary between a group of computers and external traffic.

Statomul Multilayer Inspection (SMLI) package filters on firewall networks, transportation layers, and applications, comparing them with trusted packages.

Like the NGFW firewall, SMLI also checks the entire package and allows them to graduate only when they pass each layer separately.

This firewall examines the package to determine the state of communication (thus the name) to ensure that all communication offered occurs only with trusted sources.

Advantages of firewall

  • Monitor traffic

The main responsibility of a firewall is to monitor all network traffic passing through it. Any information that travels through the network is in the form of packets. The firewall intercepts each and every data packet. If any dangerous threats are detected, it will block them immediately.

  • Protection of viruses

Some viruses especially Trojans, viruses on this side are very dangerous for the user. A Trojan silently spy on all the actions your system performs. Then whatever information it gets about your work, it will be sent to the web server.

You won’t know their presence until your computer behaves strangely. This is what a firewall does, it will block viruses like Trojans right away, before they do any harm to your system.

  • Protection of hackers

Nowadays the biggest problem of internet is to protect its system from hackers, hackers are constantly looking for some computer to carry out their illegal activities.

When hackers find computers that do not have any security arrangements, they will also start doing malicious activities like spreading viruses.

Apart from those hackers there could be unknown people like neighbors looking for open internet connection. Therefore, a firewall can be the best option for security to prevent such intrusions.

  • Access control

Firewall comes with an access policy that can be enforced for certain hosts and services. Some hosts can be exploited with attackers. So it is best to block such hosts from accessing the system.

This access policy may be enforced if the User feels that they require protection against such unwanted access.

  • Better privacy

Privacy is one of the main problems of the user. Hackers continue to seek secret information to obtain instructions about users. But many services offered by sites such as domain and finger name services can be blocked using a firewall.

Therefore, hackers do not have the opportunity to obtain privacy details. In addition, the DNS firewall may block site system information. It will not show IP name and address from attackers.

Disadvantages of firewall

  • Higher cost

Firewall is great for security but very complicated in terms of cost. It is very expensive for the users, which is the biggest disadvantage.

  • User restriction

There is no doubt that the firewall prevents invalid access from the network to your system. While this can be useful for average users, it can be a problem for really big clothes.

A policy used by firewall cabs to prevent employees from performing certain strict operations. As a result, the overall productivity of the company is greatly affected.

Sometimes this can even lead employees to use backdoor exploits. However, this can cause security problems as the data passing through the back doors is not properly scrutinized.

  • Performance

Firewalls have the potential to limit the overall performance of your computer, especially software-based ones. Processing power and RAM resources are several factors that determine the overall performance of a computer.

When software firewalls constantly run in the background, they consume more processing power and RAM resources.

This can reduce the performance of the system. However, hardware firewall does not affect system performance as it does not depend on computer resources.

  • Malware attack

Although a firewall has the ability to block basic types of Trojans, it has proven to be helpless to other types of malware. This type of malware can enter your system as a trusted data.

Therefore, even if you have a firewall, it is still recommended to install anti-malware software on your PC. Because the only way to remove it is with an anti-malware scan.

  • Complex operations

Although firewall maintenance has become easier for small businesses, certainly not for large businesses. Large clothing requires a separate employee set up to operate the firewall.

These people make sure that the firewall is secure to protect the network from intruders.


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