Choosing A Strong Firewall Is Essential When We Intend To Protect The Corporate Or Home Network From Cyber Attacks. 

A firewall is a hardware or software system that functions like a virtual wall. It is deployed at critical points and at most entrances to networks, so unauthorized clients fail to access the local area network (LAN).

Unfortunately, some users and even network and security experts buy firewalls under the influence of advertisements published on websites. At the same time, you should pay attention to important points when buying a firewall.

To be more precise, before buying, you should know about the different types of firewalls to buy a product that suits your needs. Firewalls monitor traffic going into or out of a network but do not protect computers and networks from cyber attacks.

Tips you should know before buying a firewall.

The first thing to note is that firewalls can only monitor the traffic they receive and have no control over the traffic they do not receive. Devices such as flash drives or any external memory can easily infect a system or networks deployed in the DMZ. Hence, firewalls should not be considered a substitute for antiviruses, which can detect suspicious activity and prevent the spread of malware.

An antivirus protects systems and communication networks against viruses that a firewall cannot detect. That is why firewalls and antiviruses complement each other and implement an efficient security mechanism.

Five main types of firewalls

Various brands operate in the field of security products and firewalls, and almost all of them produce and market the five types of firewalls we will mention. In general, firewalls are divided into the following five main types, depending on their function, type of protection mechanism, and set of features they provide:

1. Closed filtering firewall

Walls of firePacket-Filtering Firewalls are the most basic type of firewalls. Although they are old in terms of architecture and technical structure, they still play an essential role in cyber security. The packet filtering firewall functions like a security guard that keeps a list of people allowed to enter the building. The packet filtering firewall is deployed at the connection points of the networks and inspects the packets.

Packet filtering firewalls are popular among security experts due to their low price and high speed in traffic scanning. They check packets against a set of predefined criteria, so they drop or filter the box when they receive a package whose components don’t match their list. That is why they are called “closed filtering firewalls.”

However, they also have disadvantages. Hackers have edited the contents of the packages in such a way that the malicious packages can pass through the predetermined controls. In general, packet filtering firewalls are ideal for home users and small organizations that do not have sensitive data on their servers. Ideally, they are used as a layer of security alongside other software solutions or as part of a layered defense strategy.

2. Circuit level gateway firewall

Circuit-Level Gateway Firewalls are similar to packet-filtering firewalls, except that they can process requested transactions while filtering all traffic. In addition, circuit-level gateway firewalls are simple to set up and cost-effective. Of course, they also have disadvantages. For example, they cannot protect the communication infrastructure against data leakage from a networked device. Also, they need frequent updates to protect the network from various threats.

Ideally, they work well alongside other firewalls and as part of a layered defense. If we return to our previous analogy, we must say that these firewalls also have a function similar to a security guard with a list of people who matches the name of each person who is going to enter the building with the characters on the list and if his name is on the list They allow to pass.

The main difference between these firewalls and the previous example is that the guard constantly has access to an updated list of people who can enter or leave the building.

3. Application level gateway firewall/proxy firewall

A proxy firewall works similarly to a Cloud Secure Web Gateway in that it creates only one entry point to connect to the network through which all traffic must pass. Unlike the two firewalls we reviewed, proxy firewalls scan all packets based on parameters such as required service, destination port, etc., making identifying suspicious packages easier.

These firewalls can monitor network performance more efficiently, although due to the advanced features they provide, they are a bit difficult to manage and are more expensive than the previous ones; however, they are not capable of working with all network protocols. These firewalls are used mainly by large organizations to limit access to resources and prevent sensitive data leakage.

This firewall is the equivalent of a security guard stationed at the entrance gate with a list of people who check their profiles, asking them what they are doing, where they are going, and where they are coming from to see if there is anything suspicious. Circuit-level gateway firewalls do the same for packets going to or from terminals.

4. Stateful inspection firewall

Stateful Inspection Firewalls deeply analyze packets and payloads to identify anything suspicious. These firewalls control the content that enters or leaves the network. Like proxy firewalls, inspection firewalls are stateful and expensive, and due to the heavy monitoring they enforce, they sometimes negatively impact network speed and may cause communication interference. These firewalls are good at detecting suspicious behavior.

5. Next-generation firewall

Next-Generation Firewalls provide the highest level of security. Unlike other firewalls, an NGFW can evaluate the different applications that traffic flows through or generates. It is done through automatic updates and integration with other security techniques. Typically, firewalls next-generation offer the functions of several different security software.

NGFWs have their complexities because they use different tools and methods to evaluate Internet packets, and in addition, they are challenging to implement; Because they must integrate with the security tools deployed in the enterprise network to be able to detect threats with the least amount of false positive alerts.

The above approach is a complex process and should be done by a security expert or a company’s IT department. NGFWs are classified as the most expensive security tools in the market and require cloud computing services to perform their activities.

Due to the price and complexity, NGFWs are used mainly by organizations where all their information is sensitive and vital. Law firms, hospitals, or financial institutions use these firewalls.

6. Integrated threat management mechanism

Unified Threat Management (UTM) The name Unified Threat Management refers to a system consisting of several security services that are integrated and used as an integrated security solution. When an integrated threat management system is installed, it can protect network users using various tools such as antivirus, content filtering, email, web filtering, anti-spam, etc.

UTM enables an organization to integrate its IT security services into one system and protect the network more straightforwardly. As a result, businesses can easily manage all threats and network activity through a central dashboard. In this case, detailed reports on the performance of different network parts and any suspicious activity are obtained.

In general, “Integrated Threat Management System” and ” Next Generation Firewalls ” are the leading options companies use to protect their infrastructure because they allow simultaneous access to the firewall and security tools.

Integrated threat management systems provide various capabilities to organizations, including the following:

• Antivirus: UTM has antivirus software that can monitor the network, detect viruses and prevent viruses from infecting a system or spreading the infection to other systems. It is done using the information in the antivirus database. Some of the threats that UTM Antivirus software can stop are infected files, Trojans, worms, spyware, and malware. 

• Anti-malware: The integrated threat management system protects the network against malware threats by identifying malware and dealing with them. A UTM can protect systems by detecting known malware or filtering out suspicious packets that may be infected. UTM can also use methods such as exploratory analysis, which includes rules that analyze the behavior and characteristics of files, to detect new malware threats. 

• Sandbox: Some UTMs are equipped with a sandbox mechanism, which is an anti-malware strategy. A sandbox is a place on the systems or network to which suspicious files or software are transferred. In this case, if the malware tries to do something malicious, it will be detected quickly. 

• Firewall: By scanning incoming and outgoing traffic, firewalls help security tools detect viruses, malware, phishing attacks, spam, network intrusion attempts, and other cyber threats. Because UTM firewalls inspect network ingress and egress, they can identify devices within the network that may be spreading malware to other parts of the network. 

• Intrusion prevention: UTM systems can identify malware and prevent cyber attacks by analyzing behavior patterns and information packets. This capability is achieved through the combination of two mechanisms, the “Intrusion Detection System” (IDS) and the “Intrusion Prevention System” (IPS). An IPS analyze data packets to detect threats and looks for known patterns in threats. When one of these patterns is detected, the IPS stops the attack.

In some cases, an IDS will only detect dangerous data packets and send an alert to the IT team to take appropriate measures to counter the threat. These actions can be done automatically or manually. In addition, UTM can log malicious events; So that security experts can analyze the reports at the right time and prevent similar attacks in the future.

• Virtual private network: Another helpful feature that UTMs provide is a virtual private network (VPN), which creates a secure tunnel and allows organizations to exchange information through a secure network without worrying about eavesdropping or tampering. Have. In this mode, all data packets sent or received are encrypted.

• Web filtering: The above feature prevents the employees of an organization from visiting certain websites. So that the user’s browser cannot load the pages of the sites, you can configure web filters to block specific locations according to organizational policies. For example, if some social networks cause a distraction to users, it is possible to filter these sites using the integrated threat management system.

• Data Loss Prevention: DAP technology is a mechanism that UTM provides to organizations to detect and remediate data breaches. The data loss prevention mechanism monitors sensitive data. When it detects an attempt by a malicious actor to steal, it blocks the attempt, sends a report to the network administrator, and prevents data theft.

Three main types of firewalls

Depending on the needs of organizations, firewalls are marketed in three different models that include all or some of the modes mentioned above.

Hardware-based firewalls

The above mechanism provides a secure gateway to the corporate or home network. In most cases, hardware firewalls are located in routers and provide secure access to the Internet. Most home and business routers come with pre-installed firewalls. This model of firewalls is suitable for home networks or small work environments.

The main disadvantage of the above firewalls is that they only protect the devices behind the router. In more professional examples, firewalls are available to organizations in the form of advanced and efficient hardware equipment that requires a lot of skill to install, must be updated continuously, and relevant licenses must purchase to benefit from their capabilities.

Software-based firewalls

A software firewall provides users with all the features the hardware instance offers in virtual form. The advantage of the above method is that you can install software firewalls on any device you need.

The main disadvantage of software firewalls is that they use system resources, such as the CPU and main system memory. These firewalls protect electronic equipment that will be installed and used in public places. It is necessary to explain that some are free and others are paid. For example, TinyWall is an excellent example of a free software firewall.

Cloud-based firewalls

Cloud-based firewalls are sometimes referred to as cloud firewalls and firewalls as a service (FWaaS). The cloud firewall has the same functionality as the previous two options. The difference is that this type of firewall provides the necessary security between the cloud infrastructure and the networks.

last word

As you can see, different firewalls are designed to meet users’ needs. Whether you are a user looking to strengthen your communications infrastructure or an organization looking to protect data and prevent leaks, you should know that having a firewall is not an option but a necessity.

You need to consider what type of firewall is suitable for what purpose. For this reason, it is recommended to carefully check the advantages and disadvantages of each one before buying firewalls to buy an option that suits your needs.