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As we’re living in the age of cybercrime and more businesses are prone to cyber attacks, having a firewall is nowadays more important than ever. They can save you a massive headache and can prove detrimental to the success of your business. If you don’t know much about them but want to find out, you’ve come to the right place. Our article will give you all the critical info you need and help you get started with firewalls!

What is a Firewall?

The term ‘firewall’ represents a literal wall that prevents fires from spreading in buildings, vehicles, or any other closed spaces. What a firewall does is that it gives extra time for occupants to escape the fire and leave unharmed. Like this type of firewall, a software/hardware firewall works the same way, not letting fire, that is, cyber-attacks, or breaches through any computer’s entry points. Firewalls only let trusted source addresses enter the destination address, ensuring there’s no suspicious activity on your network.

What Is the Purpose of a Firewall?

A top-notch firewall will protect your business from:
  • Remote logins – Firewalls protect you against unauthorized access to your devices via the internet, so you won’t have to worry about cybercriminals who can steal your information or install malware on your network.
  • Email hijacking – If access to your network falls into the wrong hands, your contacts will be at risk of receiving malicious emails. This can cause a massive blow to your business’s reputation, which an effective firewall will protect by ensuring it never comes to email hijacking.
  • Email bombs – In the same way, a cybercriminal can send loads of malicious emails, they can also send the same message to a server that causes a crash.
  • Viruses – Viruses are the biggest threat from cybercriminals as the global damage of malware attacks was over $4.4 trillion, only in 2021. They can spread quickly through your network and system, slow down your devices, delete your data, etc. A firewall will block viruses before they even get the chance to infiltrate the network.

Different Types of Firewalls

Packet Filtering Firewall

A packet filtering firewall is a low-cost firewall option best suited for small or budget-constrained businesses as it provides security on a fundamental level against known threats. This option is also good for businesses that want to use filtering as a layered defense and dodge harmful traffic. Packet filtering firewalls operate at the network layer and check the following data packet elements to determine whether to pass them or discard them:
  • Source IP
  • Destination IP
  • Protocol
  • Source port
  • Destination port
This type of firewall monitors each packet independently without any track of the established connection or the information on whether the packet has passed through the connection previously. This is what makes these firewalls limited and essential. Check out the table below to see their pros and cons:
Pros Cons
Cheap and affordable Lacks broader context that informs other types of firewalls
Minimal effect on other resources and end-user experience Doesn’t check the payload
Fast and efficient in scanning traffic It can easily be spoofed
One device can filter the whole network It’s challenging to set up and manage access control lists

Circuit-level Gateway

Circuit-level gateway firewalls are similar to packet filtering firewalls as they perform a single check and use as few resources as possible. They determine the security of an established connection by establishing a virtual connection on behalf of the internal device when an internal device initiates a connection to keep the identity and IP address of the internal user hidden. Although this type of firewall is affordable and efficient at the same time, it cannot inspect the content of data packets. A data packet with malware can easily bypass the circuit-level gateway and wreak havoc in the system. Usually, most businesses add another firewall on top of a circuit-level gateway firewall to have complete protection. See all the advantages and disadvantages of circuit-level gateway firewalls in the table below:
Pros Cons
Budget-friendly Doesn’t offer any protection against data leakage if it isn’t paired with other security technology
Processes requested transactions and reject other traffic No application-layer monitoring
Easy to set up Dependant on constant updates to keep rules current
Minimal impact on end-user experience

Application-level Gateway

Also known as proxy firewalls, these firewalls establish a connection through the proxy firewall instead of letting outsiders access your internal network. The external client needs to request entry to the proxy firewall, which verifies the request’s authenticity and forwards it to one of the internal devices on the client’s behalf. If an internal device requests access to your webpage, the proxy device will forward the request and hide the identity of the network at the same time. Proxy firewalls protect your resources’ identity and location by preventing a direct connection between external networks and external systems. The downside is that configuring them can be tricky if you want to have optimal protection. See other downsides as well as the upsides in the table below:
Pros Cons
Examines all communications between outside sources and devices as well as the content itself Can slow down traffic considerably
Protects user anonymity More expensive than other options
Creates their own dynamic rules Requires a lot of effort to get the maximum benefit from the gateway
Isn’t optimized for all network protocols

Stateful Inspection Firewall

Stateful inspection firewalls verify and keep track of established connections while inspecting data packets to provide a higher level of security. Once a connection is established, these firewalls create a state table with the following elements:
  • IP
  • Destination IP
  • Source port
  • Destination port
What makes stateful inspection firewalls a solid protection layer is that they don’t rely on a hardcoded set of rules to allow expected incoming traffic. Instead, they create their own dynamic set of rules. They check for legitimate connections and destination IPs to determine whether a data packet can pass through or not. The downside is that they consume a lot of system resources at the cost of extra checks. Check out the table below to see all their ups and downs:
Pros Cons
Checks the IP addresses and payloads while monitoring the entire session for the state of connection Interferes with the speed of network communications
Doesn’t need to open a lot of ports to allow traffic Prone to DDoS attacks (distributed denial of service attacks)
Offers a lot of control over what content is let in or out Consume a lot of system resources
Can slow down traffic

Next-Generation Firewall

Next-generation firewalls offer additional security features while overcoming the limitations of old-school firewalls. What makes them next-gen is their ability to combine packet inspection with stateful inspection while also including deep packet inspection and IDS/IPS, malware filtering, antivirus, and other network security systems. This type of firewall combines the features of other firewalls without sacrificing any features and without affecting network performance. They do have their disadvantages and benefits too, such as:
Pros Cons
Combines various security systems and provides a high level of security More expensive than other firewall types
Tracks all traffic Businesses need to integrate this firewall with their other security systems, which can be a complex procedure

Should You Get a Firewall?

Having a firewall significantly reduces the risk your business faces against cyber attacks. Without one, you can easily fall victim to cybercriminals and lose important data and other assets, time, etc. A finely tuned firewall will allow you and your team to work undisrupted without having to worry about security. A proper MSP can configure and manage your firewalls in your stead, letting you focus on work and productivity. So, if you want to save money and reduce maintenance time and cost, you should definitely get a firewall and an MSP to help you set it up and manage it properly. If you don’t know where to get started, feel free to contact our team of experts and schedule a free consultation to find out everything you need about setting up a high-quality firewall.

About the author

Slobodan Krsmanovic, the CEO of TechProComp, brings over 25 years of deep-rooted experience in the IT industry. As the author driving our insightful posts, Slobodan embodies a steadfast commitment to client-centric service, fostering respectful and secure collaborations across all business scales.

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