What are the Different Types of Firewalls?

People and corporations can store confidential material on their systems to keep cybercriminals at bay. Firewalls are critical to network security since they can secure the network from various attacks. As there are various types of firewalls, a question arises: Which type of firewall will be appropriate for one’s network.

So, in this article, we will discuss different types of firewalls. But before proceeding any further, let’s go through the topics that we will be covering in this blog:

• What is a Firewall?
• Different Types of Firewalls
  • Packet Filtering Firewalls
  • Stateful Inspection Firewalls
  • Circuit-Level Gateways
  • Proxy Firewalls
  • Next-Generation Firewalls 
  • Software Firewall
  • Hardware Firewall
  • Cloud Firewall
• Conclusion

What is a firewall? 

A firewall is a tool that monitors incoming and outgoing network traffic and can detect and prevent suspicious packets of data on the basis of predefined rules, letting only genuine traffic gain entry into your private network. The most basic way to add additional security between a system and malicious attacks is to install a firewall.

You can use firewalls in both business and home settings. They are an essential part of network security. Most operating systems include a basic firewall. Using a third-party firewall application, on the other hand, provides better protection.

Different types of firewalls

There are many different types of firewalls, depending on their operation. Some of the most common firewalls are:

Packet filtering firewalls

Packet filtering firewalls are the most traditional type of network layer firewall. A static firewall is another name for this firewall. This firewall monitors incoming and outgoing packets and allows them to pass or fail based on the source and destination IP addresses, ports, and protocols. Packet filtering firewalls are quick, inexpensive, and effective. However, the security they offer is fundamental. Because these firewalls cannot analyze the content of data packets, they cannot protect against malicious data packets originating from trusted source IPs.

Some of the benefits and drawbacks of this type of firewall are:

Advantages	Drawbacks
Low resource consumption	IP spoofing is possible
More affordable	There is no user authentication
Filtering headers is quick and efficient	There is no payload.

Stateful inspection firewalls

You can use this type of firewall to control how data packets pass through a firewall. These firewalls can determine whether a packet belongs to a specific session or not. It only allows communication if the session between two endpoints is perfectly established; otherwise, it will block communication. Even though these security requirements offer advanced security, they consume many system resources and can significantly slow down traffic. As a result, they are vulnerable to DoS attacks. This kind of firewall is also known as dynamic packet filtering.

You can also explore- What is a Denial-of-Service (DoS) Attack?

Some of the benefits and drawbacks of this type of firewall are:

Advantages	Drawbacks
It records the entire session	It takes a lot of resources.
Examines packet headers and payloads	There is no user authentication support
Provides more control	DoS attacks are possible

Circuit-level gateways

A circuit-level gateways firewall operates at the OSI model’s session layer, monitoring TCP (Transmission Control Protocol) connections and sessions. Their foremost objective is to guarantee the safety of the established connections. Circuit-level gateways are inexpensive, simple, and have little impact on network performance. Their incapability to check the content of data packets, however, renders them an insufficient security solution on their own. A data packet containing malware can easily avoid a circuit-level gateway if it has a valid TCP handshake.

Some of the benefits and drawbacks of this type of firewall are:

Advantages	Drawbacks
Cost-efficient	There is no content filtering
Avoid exposing your address	There is no application layer security
Examine TCP handshakes	Requires software modifications

Proxy firewalls

You must use a proxy device to implement a proxy firewall, also known as an application-level gateway. Instead of an outsider directly accessing your internal network, the proxy server intercepts the message whenever a client requests to connect to a web page. The proxy transmits the message to the web server while posing as the client. This conceals the client’s location and identity, cloaking them from any restrictions or possible threats.

Some of the benefits and drawbacks of this type of firewall are:

Advantages	Drawbacks
Protects client data such as geolocation	Performance may suffer
Maintain user anonymity	Not all network protocols are supported
Protects against various attacks	Additional configuration is required to ensure overall encryption

Next-generation firewalls

A next-generation firewall goes beyond the capabilities of a traditional, stateful firewall. A traditional firewall typically provides stateful inspection of incoming and outgoing network traffic; however, a next-generation firewall includes features such as integrated prevention systems, application awareness and control, and cloud-delivered threat intelligence.

Some of the benefits and drawbacks of this type of firewall are:

Advantages	Drawbacks
Deep inspection is integrated	Requires a lot of system resources
Upgrades happen automatically	Expensive in comparison to other options
Keep track of network traffic from Layer 2 to Layer 7	Integration with existing security management systems may necessitate additional configuration.

Software firewall

A software firewall protects our computers. If you have multiple devices, you must install the software on each one. Because it must be compatible with the host, you must configure it individually for each. This type of firewall can safeguard our system against external threats such as unauthorized access, malicious attacks, etc. The firewall alerts you to the danger of opening a specific email or attempting to access an insecure website.

Some of the benefits and drawbacks of this type of firewall are:

Advantages	Drawbacks
Simple to set up or reconfigure	Requires a lot of system resources
Suitable for personal or domestic use	Not suitable for situations where response times are critical
Less expensive in comparison to other options	It can be challenging to remove or uninstall a software firewall completely

Hardware firewall

A hardware firewall is a physical piece of equipment that filters traffic to and from a computer, similar to a server. Usually, a network cable is plugged directly into a computer or server, but with a hardware firewall, the cord is connected directly into the firewall first. This firewall inspects outbound and inbound network traffic because all network links pass through it. As a result, access controls and other security policies are enforced. This is also known as an Appliance Firewall.

Some of the benefits and drawbacks of this type of firewall are:

Advantages	Drawbacks
Allows for faster response times	More expensive than a software firewall
Can handle increased traffic loads	Installation is difficult
Less vulnerable to attacks	Upgrading is quite difficult

Cloud firewall

These firewalls can control the flow of information between external domains and your internal system. A cloud firewall, as opposed to traditional firewalls, filters data at the cloud level. These firewalls helps to combat today’s advanced threats and safeguard your operation’s data.

You can also explore- AWS Firewall Manager

Some of the benefits and drawbacks of this type of firewall are:

Advantages	Drawbacks
Simple to deploy and scale as needed	Expensive in comparison to other options
There is no hardware involved	The availability is contingent on the availability of the cloud infrastructure
In the event of an issue, you can take snapshots and quickly recover to the desired state	Operating enhanced security features can cause the network to slow down

Conclusion

Firewalls will remain an essential component of any organization’s security solution, whether in the data center, network, or cloud, as the cybersecurity landscape evolves and attacks become more sophisticated. A firewall’s main aim is to allow non-threatening data traffic while preventing suspicious or undesirable data traffic by shielding the machine from malware and intrusions. So, rather than being sorry for not using one, use one!