Complete 5 Types of Firewalls In Computer Network



Are you looking for the best firewall configuration to safeguard your company against threats?

Firewall is a security tool that keeps an eye on network traffic. It protects the internal network by filtering incoming and outgoing traffic by preset criteria. The easiest technique to increase protection between a system and malicious assaults is to set up a firewall.

Your knowledge of firewall operation aids your decision-making process. This article describes the types of firewalls so that you may choose one that best suits your needs. It makes the somewhat arbitrary claim that there are five main categories of firewalls, each of which employs a different technique to detect and block harmful traffic. Three other firewall deployment options are also available, which we will go over in more depth.

How do the various types of firewalls function?

Traditionally, firewalls are installed inline across a network connection to monitor all traffic moving through that point. They are responsible for distinguishing between packets that are a part of an attack and safe network protocol traffic as they go.

Firewalls keep an eye on traffic and compare it to pre-defined rules that filter out hazardous stuff. Even though no security solution can fully forecast the intent of every piece of information, advancements in security technology allow for the use of recognized patterns in network data that have previously indicated assaults on other businesses.

Every firewall implements rules that specify the circumstances under which a certain packet—or collection of packets in a transaction—can be safely sent to the intended receiver.

Five Different Types Of Firewalls

  • Application-Level Gateway 
  • Stateful Inspection Firewall
  • Packet Filtering Firewall
  • Circuit-Level Gateway
  • Next-Generation Firewall (NGFW)

1. Application-Level Gateway

This type of device, which is technically a proxy but commonly referred to as a proxy firewall, serves as the network’s sole entrance and departure point. In addition to the service for which they are intended, as indicated by the destination port, application-level gateways filter packets depending on several variables, including the HTTP request string.

Although gateways that filter at the application layer offer significant data protection, they can significantly slow down a network and be challenging to administer.

Benefits :

  • Before allowing any traffic to travel via the proxy, examines all communications between external sources and devices within, evaluating the address, port, and TCP header information and the actual content.
  • offers granular security restrictions that, for instance, permit access to a website but limit which pages a user may open
  • maintains user privacy


  • Can impair the functioning of networks
  • greater cost than some other options
  • requires a significant amount of work to get the most out of the gateway
  • Not compatible with every network protocol

For the best protection against attacks from online applications, employ application-layer firewalls. They can restrict access to dangerous websites and stop the firewall from leaking sensitive data. However, they could cause a lag in communication.

2. Stateful Inspection Firewall

State-aware devices track whether a packet is a part of an active TCP or another network session in addition to inspecting each packet. While providing better security than either circuit monitoring or packet filtering, this has a bigger negative impact on network performance.

The multilayer inspection firewall, which considers the flow of transactions across many protocol levels of the seven-layer Open Systems Interconnection (OSI) architecture, is another variation on stateful inspection.


  • To provide more comprehensive security, examine IP addresses, payloads, and the session as a whole for connection status.
  • It offers extensive user control over whether or not the network accepts material.
  • does not need to enable traffic into or out of many ports
  • provides effective logging abilities


  • requires a lot of resources and slows down network connectivity
  • more costly than alternative alternatives
  • does not offer authentication features to verify that the traffic sources are genuine.

The usage of a stateful inspection firewall is advantageous to the majority of enterprises. These units act as a more comprehensive gateway between computers, other assets housed within, and resources located outside the company. Additionally, they can successfully protect network devices from specific threats like DoS.

3. Packet-Filtering Firewalls

Packet filtering firewalls run inline at intersections where devices like routers and switches work. These don’t route packets; instead, they examine each one against a set of pre-established criteria, including the permissible IP addresses, packet types, ports, and other data from the headers of packets. Generally speaking, difficult packets are unceremoniously discarded, which means they are not transmitted and eventually vanish from existence.


  • A single device may filter the entire network.
  • rapid and effective traffic scanning
  • Inexpensive
  • There is little to no impact on other resources, network performance, and user experience.


  • Packet filtering lacks a broader context that other types of firewalls rely on since traffic filtering is exclusively focused on IP address or port information.
  • does not verify the payload and is readily spoofable
  • Not always the best choice for networks
  • Setting up and managing access control lists may be challenging.

Even though packet filtering is a cheap, it may not always offer the level of security required for all use cases. Packet filtering provides a fundamental security level to protect against known threats for small or budget-constrained businesses. Larger organizations can additionally employ packet filtering as a layer of security to sift through internal departmental communication for potentially hazardous content.

4. Circuit-Level Gateways

Circuit-level gateways keep track of TCP handshakes and other network protocol session initiation signals as they are formed between local and distant sites across the network to determine whether the connection is authentic and whether the remote system is trusted. This is another technique for spotting fraudulent information that is relatively rapid. They don’t, however, inspect the packets directly.


  • All other communication is denied; only requests for transactions are processed.
  • Simple to set up and operate
  • Low price and little effect on customer experience


  • Circuit-level gateways provide no defense against data leakage from devices inside the firewall if they aren’t used in combination with other security solutions.
  • No monitoring of the application layer
  • changes is necessary to maintain the rules up to date.

Although packet filtering are less secure than circuit-level gateways, they should still be used in combination with other systems. For instance, application-level gates are frequently used in conjunction with circuit-level gateways. This approach combines content filtering with the benefits of packet- and circuit-level gateway firewalls.

5. Next-Generation Firewall

A typical NGFW combines packet inspection with stateful inspection, some form of deep packet inspection (DPI), and additional network security tools like an IDS/IPS, malware filtering, and antivirus.

DPI examines the actual data that a packet carries, as opposed to classical firewalls that check the protocol header of the packet. When a packet payload is combined with additional packets in an HTTP server reply, a DPI firewall that monitors web browsing activity can determine if the result is a valid HTML-formatted answer.


  • provides the best screening level by combining DPI with malware filtering and other controls.
  • Compared to other techniques, it tracks all traffic from Layer 2 to the application layer to provide more precise insights.
  • Automatic updates are possible to offer relevant context.


  • Organizations must integrate NGFWs with other security systems to get the most advantage, which may be challenging.
  • expensive than other forms

NGFWs are a vital safety net for businesses in highly regulated sectors like healthcare or finance. These multipurpose capabilities appeal to individuals who have a firm understanding of precisely how dangerous the threat environment is. The best results from NGFWs come from integrating with other security systems, which frequently necessitates a high level of knowledge.

A Guide to Connecting Your WiFi Extender: A Step-by-Step Approach

In this tutorial, we will provide a comprehensive guide to connecting your WiFi extender. We will take you through the process step-by-step, ensuring that you are able to connect your WiFi extender with ease. Whether you are new to the process or have had difficulties in the past, we will provide the information you need to connect your WiFi extender successfully.

Three Different Firewall Deployment

1. Hardware-Based Firewalls

An appliance known as a hardware-based firewall serves as a secure gateway for devices inside and outside the network boundary. Hardware-based firewalls don’t suck up the host devices’ processing power or other resources because they are standalone appliances.

These devices, also known as network-based firewalls, are perfect for medium- and large-sized businesses needing to safeguard numerous devices. Compared to host-based firewalls, hardware-based firewalls require greater technical expertise to set up and maintain.

2. Software-Based Firewalls

A server or other device hosts a software-based firewall, also known as a host firewall. Each device that needs security must have host firewall software installed. Software-based firewalls use part of the CPU and RAM of the host device as a result.

Individual devices benefit significantly from the security offered by software-based firewalls against viruses and other harmful information. They can distinguish between the several hosts’ running programs and filter incoming and outgoing traffic. With such fine-grained control, it is conceivable to allow communications to/from one application while disabling them to/from another.

3. Cloud/Hosted Firewalls

Cloud-based firewalls are available from managed security service providers (MSSPs). This hosted service may be set up to monitor both in-house network activities and external on-demand settings. Cloud-based firewalls, sometimes referred to as firewalls as a service, may be fully managed by an MSSP, making them an excellent option for large or dispersed enterprises that lack the security resources. Smaller businesses with fewer resources in terms of employees and knowledge can also benefit from cloud-based firewalls.

Which firewall is the best option for your company?

Answering questions regarding what the firewall protects, which resources the business can afford, and how the infrastructure is designed is necessary when deciding on the best firewall. The ideal firewall for one company might not be suitable for another.

How to Detect Phishing and Protect Your Information

In this article, learn how you may recognize and avoid phishing scams and safeguard your data from attackers, which also discusses the various phishing techniques used by hackers.


Finding a firewall that perfectly fits into any category is uncommon since many implementations combine features from several types of firewalls. An NGFW, for instance, may combine new capabilities with a few from stateful inspection firewalls, application-level gateways, and packet filtering firewalls.

The first step in choosing the ideal firewall is understanding the architecture and operations of the private network to be secured. Still, it also requires knowledge of the various firewall types and policies that work best for the organization.

Regardless of the types of firewalls you select, remember that a poorly designed firewall may, in some cases, be worse than having none since it creates a hazardous false sense of security while offering minimal to no protection.

Related Articles