27.08.2023

Choosing the Right Firewall For You: An In-Depth Look at 8 Distinct Types

27.08.2023
types-of-firewalls

Network security is increasingly important in an evolving digital landscape. The firewall is the heart of this solution, protecting your business’s critical information from cyber threats. 

But with so many types available, how do you choose the right one?

In this article, we look at the eight types of firewalls, their features, and how to choose which one is right for you.

What is a Firewall? 

Picture a firewall as a vigilant security guard, ceaselessly monitoring traffic flow to and from your network, always ready to thwart potential threats. This digital protector’s primary role is to form a robust barrier, admitting safe traffic while repelling malicious intruders.

Just like a physical security guard, a firewall’s duties can vary based on the context. In the world of network security, firewalls:

  • Safeguard entire networks from potential threats originating from the internet.
  • Create secure “compartments” within internal networks (for instance, preventing HR personnel from accessing systems meant solely for the DevOps team).
  • Shield individual devices from harmful traffic (for instance, protecting a personal laptop used for work, or BYOD, from suspicious incoming traffic).

Consider firewalls as the steadfast pillars of network security in the client-server model. They scrutinize both incoming and outgoing traffic to ensure their safety. However, just like humans, they:

  • Falling victim to social engineering attacks (such as when a password is stolen to impersonate the CEO).
  • Internal threats (like a disgruntled employee intentionally tampering with the firewall settings).
  • Unintentional errors (like an employee forgetting to activate the firewall or disregarding update notifications).

Why Do You Need a Firewall? 

Firewalls and technologies like Secure Access Service Edge (SASE) and Zero Trust Network Access (ZTNA) serve as the first line of defense against cyberattacks, shielding your computers and network from malicious or unnecessary network traffic. Moreover, they can thwart malicious software from accessing your system online.

Imagine your workstation without a firewall—it would be like leaving your house’s front door wide open, inviting burglars in. Once your workstation is compromised, so too is your cloud-based data. 

Simply put, without a firewall, your data is at risk. A firewall, however, is just one component of a comprehensive and effective network security infrastructure.

5 Most Common Types of Firewalls

There are several types of firewalls, each with its own unique way of protecting your system. Let’s examine five of the most common types of firewalls.

Packet Filtering Firewall

Packet Filtering Firewalls, functioning at critical junctions like routers and switches, examine every packet against established criteria such as IP addresses, packet types, port numbers, and other packet protocol headers. Suspicious packets are typically dropped, not forwarded, and therefore cease to exist.

Pros

  • It can filter traffic for the entire network with a single device.
  • Extremely efficient and fast at traffic scanning.
  • Inexpensive and resource-friendly, with minimal impact on network performance and user experience.

Cons

  • It lacks a broader context, as filtering is purely based on an IP address or port information.
  • It does not inspect the payload and hence, is susceptible to spoofing.
  • It is not the optimal choice for all networks due to the complex setup and management of access control lists.

Circuit-Level Gateway

Circuit-level gateways provide security by monitoring TCP handshakes and network protocol session initiation messages across the network. This checks if the session initiated is legitimate or if the remote system is deemed trustworthy without inspecting the packets themselves.

Pros

  • Processes only requested transactions, rejecting all other traffic.
  • Simple to set up and manage.
  • Low-cost solution with minimal impact on user experience.

Cons

  • Without complementary security technology, these gateways offer no protection against data leakage from devices within the firewall.
  • No application layer monitoring.
  • Requires consistent updates to keep rules current.

Application-Level Gateway (Proxy Firewall)

An Application-level gateway, technically a proxy or proxy firewall, serves as the network’s sole entry and exit point. It filters packets based on various characteristics, including the destination port and the HTTP request string. Although these gateways provide substantial data security, they can significantly affect network performance and be challenging to manage.

Pros

  • Inspects all communications between outside sources and internal devices, even checking the content before allowing traffic through the proxy.
  • Provides granular security controls.
  • Maintains user anonymity.

Cons

  • May slow down network performance.
  • More expensive than some other firewall options.
  • Requires considerable effort to maximize the benefits from the gateway.
  • Not compatible with all network protocols.

Stateful Inspection Firewall

Stateful Inspection Firewalls examine each packet while keeping track of whether that packet is part of an established TCP or other network session. This dual function provides more security than packet filtering or circuit monitoring alone but may affect network performance.

A multilayer inspection firewall, a variant of stateful inspection, considers transactions across multiple protocol layers of the seven-layer Open Systems Interconnection (OSI) model.

Pros

  • Monitors the entire session and checks IP addresses and payloads for enhanced security.
  • High degree of control over what content enters or leaves the network.
  • Doesn’t require numerous ports to be opened.
  • Offers substantial logging capabilities.

Cons

  • Resource-intensive, which can hinder network communication speed.
  • More costly than other firewall options.
  • Lacks authentication capabilities to validate traffic sources.

Next-Generation Firewall (NGFW)

NGFWs combine packet inspection with stateful inspection, often including deep packet inspection (DPI), intrusion detection/prevention systems (IDS/IPS), malware filtering, and antivirus features. While packet inspection in traditional firewalls focuses only on the protocol header, DPI examines the actual data the packet is carrying, thus enhancing the scrutiny level.

Pros

  • Integrates DPI with malware filtering and other controls for optimal filtering.
  • Tracks all traffic from Layer 2 to the application layer for more accurate insights.
  • Supports automatic updates to provide current context.

Cons

  • To maximize benefits, NGFWs need to be integrated with other security systems, which can be complex.
  • More expensive than other types of firewalls.

Comparing the pros and cons of the different types of firewalls

Firewall typeProsCons
Packet filtering firewallsFilters entire network traffic with a single device. Fast and efficient packet processing. Supports complex security policies via protocol header filtering. Cost-effective and low impact on network performance.Can’t filter at the application layer. Limited contextual understanding compared to other firewalls. Secure configuration can be challenging. Lacks user authentication and logging features.Vulnerable to spoofing attacks. Access control lists setup can be complicated.
Circuit-level gatewaysEnsures data privacy in private networks. More efficient than application-level gateways. Budget-friendly and easy to manage. Minimal impact on users. Protects network sessions, not just individual packets.Requires changes to the network protocol stack. No content filtering. Needs to be used with other firewall technologies. Lacks application-layer monitoring.
Application-level gatewaysCan detect and block hidden attacks. Hides private network details. Provides fine-tuned security controls. Protects user anonymity.Complex to configure and maintain.High processing load. Each network application requires a proxy setup. May slow down network performance.
Stateful inspection firewallsCan block protocol vulnerability exploits. Operates with fewer open ports. Blocks many types of denial-of-service attacks.High skills are required for secure configuration. Doesn’t support authenticated connections. Ineffective against stateless protocol exploits. High processing load.
Next-generation firewallsCombines traditional firewall functionality with IDS/IPS, threat intelligence, malware scanning, and more. Monitors network protocols from the data link layer to the application layer. Provides comprehensive logging capabilities. More efficient than combining firewalls plus IDS/IPS and malware scanning.Single point of failure due to function consolidation.High initial resources investment. May be processing-intensive, depending on the architecture. Not all functionality is required by every organization. May slow down network performance. More expensive than other firewall options.

3 Types of Firewall Delivery Methods

Selecting a firewall delivery method can significantly influence your network protection strategy’s security, functionality, and cost-effectiveness. Here’s a concise breakdown of three common firewall delivery methods.

Hardware Firewall

The hardware firewall, also called an appliance firewall, is an independent piece of hardware that manages and filters incoming and outgoing traffic for an entire network. These devices are autonomous, meaning they don’t tap into host devices’ CPU or RAM resources. 

While smaller businesses might find these excessive, larger organizations with numerous interconnected computers and subnetworks often find them indispensable.

Pros

  • Shields multiple devices through a single solution.
  • Provides robust perimeter security, ensuring harmful traffic doesn’t reach host devices.
  • Saves host devices from unnecessary resource consumption.
  • Simplifies administration with a single firewall for the entire network.

Cons

  • Typically costlier than software firewalls.
  • Vulnerable to insider threats.
  • Requires more expertise to configure and manage than software-based firewalls.

Software Firewall

The software firewall, or host firewall, is installed directly onto a specific device, such as a PC, laptop, or server. Because it protects only the device it’s installed on, administrators must install the software on each device they wish to safeguard. As these firewalls are device-specific, they unavoidably use some system resources, which might be a drawback for certain users.

Pros

  • Provides top-notch protection for the assigned device.
  • Isolates individual network endpoints from one another.
  • Offers granular security, giving administrators full control over allowed programs.
  • Widely available.

Cons

  • Consumes the device’s CPU, RAM, and storage resources.
  • Requires individual configuration for each host device.
  • Routine maintenance can be challenging and time-intensive.
  • Not universally compatible, possibly requiring different solutions within the same network.

Cloud Firewall

Cloud-based firewalls, also known as Firewall-as-a-Service (FaaS), are on-demand services delivered over the internet, operating either as IaaS or PaaS. 

Managed by a service provider, cloud firewalls are a great fit for distributed businesses, teams with security resource shortages, and organizations lacking in-house expertise. 

These firewalls excel at perimeter security like hardware-based solutions but can also be configured per host.

Pros

  • Service provider handles all administrative tasks, including installation, deployment, patching, and troubleshooting.
  • Scalable according to traffic load without the need for in-house adjustments.
  • No requirement for in-house hardware.
  • High levels of availability.

Cons

  • Uncertainty about the provider’s specific firewall management practices.
  • Migration to a new provider can be challenging, as with other cloud-based services.
  • Raises latency and privacy concerns as traffic flows through a third party.
  • Long-term operational costs can be high.

Firewalls vs. VPNs

While firewalls and VPNs are both key elements in the arena of network security, they perform their roles in distinctly different ways. Think of a firewall as your network’s doorman, controlling and screening the traffic that comes in and goes out, while a VPN is like your network’s personal invisibility cloak, encrypting your online activities and hiding them from any unwanted gaze.

If you’re employing both a firewall and a VPN, it’s crucial to remember that the VPN should be installed behind the firewall. Why? Because the firewall is akin to the sturdy gate protecting your entire network (including the VPN server) from the vast, often perilous internet.

At times, your vigilant firewall might block certain ports often used by VPNs. If your data tries to pass through one of these blocked ports, the firewall will stand its ground, not allowing it to pass through. This can hinder your VPN communication.

The process of setting up a VPN behind a firewall varies depending on the tools used. However, here’s a general step-by-step guide for setting up a VPN behind a firewall using Google Cloud:

  1. Navigate to the VPN tunnels page in the Google Cloud console.
  2. Select the VPN tunnel that you want to use.
  3. In the VPN gateway section, click on the name of the VPC network.
  4. Switch to the Firewall rules tab.
  5. Click on “Add firewall rule.”
  6. Complete the necessary fields, and then click on “Create.”

Tips for Choosing the Right Firewall For Your Business

Choosing the perfect firewall isn’t just about ticking off features from a checklist, but it’s about aligning it with what your business aims to safeguard, what resources it can allocate, and how its IT infrastructure is built.

Remember, one size doesn’t fit all here—a firewall that perfectly suits one organization may fall short for another.

Before plunging into the sea of firewalls, it’s essential to have a compass in the form of a clear understanding of your business’s unique needs and context. The following steps will help you navigate this crucial process to select a firewall solution that fits snugly into your business’s landscape.

Decide on Your Preferences

The first step on this journey is defining your key preferences. Are you hunting for a comprehensive security solution or a dedicated firewall? How much control would you like over the firewall’s configuration? Do you prefer an on-premise solution, or are you open to a cloud-based one? Reflecting on these questions will guide your search in the right direction.

Look at the Security Infrastructure

The blueprint of your existing security infrastructure is an essential guidepost. The new firewall should blend smoothly with your current systems and tools, bolstering rather than complicating your security stance. Analyze your network layout, traffic patterns, and potential weak spots to ascertain how the new firewall can best fortify your defense.

Evaluate the Cost

Your decision should factor in not just the initial price tag of the firewall but also the recurring expenses for upkeep, updates, and potential add-ons. It’s important to weigh your budget limits against the long-term value you expect from the firewall. Keep in mind the priciest option isn’t always the one that offers the best value for your business.

Deciphering the Types of Firewalls for Optimal Network Security

In an age where cybersecurity risks are constantly escalating, understanding the various types of firewalls and their distinctive features is critical. The choice of firewall can significantly impact your business network’s security, efficiency, and resilience. 

Whether it’s packet filtering, stateful inspection, or any of the other firewall types we’ve explored, the right selection hinges on your specific business needs, network infrastructure, and the level of protection desired. 

As we’ve seen, firewalls serve different purposes and offer unique advantages, so taking the time to discern your specific requirements will undoubtedly pay off. 

Remember, safeguarding your digital assets is not just about implementing a firewall, it’s about choosing the right one.

Are you ready to enhance your network security and boost your business’s resilience with a dynamic firewall solution that offers customized protection? Craving peace of mind in this era of cyber threats? Click here to experience a free demo of Perimeter 81 and discover the benefits of superior threat detection, advanced customization, and seamless integration.

FAQs

What are the 5 types of firewalls?
Packet-filtering firewalls: This is considered the most basic firewall type, but don’t be fooled—it’s worthwhile. They filter traffic based on specific rules that apply to the network and, in some instances, transport layers. However, they only examine a packet’s header.

Circuit-level gateway firewalls: Another basic firewall type, circuit-level gateways primarily function in the session layer, handling TCP handshakes and other connection-related mechanisms. They inspect these messages and match them against preset session rules to determine the legitimacy of a session.

Application-level gateway firewalls (Proxy firewalls): Operating at the highest OSI and TCP/IP layers— the application layer— these firewalls perform deep packet inspection (DPI) and can even prevent direct communication between two devices while still giving the impression of a direct connection.

Stateful inspection firewalls: Operating in the network and transport layers, these firewalls scrutinize packets and check their alignment with the firewall’s ruleset before letting them pass.

Next-generation firewalls: NGFWs pack advanced features like DPI, intrusion detection system/intrusion prevention system (IDS/IPS), and malware protection on top of basic packet filtering and stateful inspection.
What are the 3 methods of firewall?
Hardware-based firewalls: Also known as appliance firewalls, these are standalone devices that provide firewall capabilities and are typically positioned at a network’s perimeter, serving as gatekeepers between internal and external networks.

Software-based firewalls: Also referred to as host firewalls, these are software applications installed on devices to provide granular security, often more aware of the device’s processes due to their dedicated installation.

Cloud firewalls (Hosted firewalls): Also known as Firewall-as-a-Service (FaaS), cloud firewalls are third-party managed services that provide firewall capabilities, taking care of all administrative tasks from installation to troubleshooting.
What is the strongest type of firewall?
Proxy firewalls earn the title of the most robust type, serving as middlemen where source computers connect to the proxy rather than the destination device, ensuring optimal security.
What is the most secure type of firewall?
Proxy servers secure the top spot as the most secure type of firewall. They filter packets through a protected proxy server before traffic reaches the network perimeter.
What is the simplest type of firewall?
The packet-filtering firewall is the most basic form of protection. It is a management program that can block network traffic based on IP protocol, IP address, and port number, making it suitable for smaller networks.