One of the major problems every company faces when trying to secure their sensitive data is finding the right security tools. Often, even when it comes to common tools like firewalls or network firewalls, businesses do not know how to choose the right firewall that fits their needs, how to configure the firewall, or why a firewall is important for their business.
But do not worry. Here in this post, we have discussed everything you need to know about a firewall and the different types of firewall that are available online which will cater to your specific business needs.
What is a Firewall?
A firewall is a type of cybersecurity tool that is used to filter traffic on a given network. Firewalls are used to separate network nodes from internal and external traffic sources or even from specific applications. There are three types of firewalls: software, hardware, cloud-based security tools, and each has its advantages and disadvantages.
The main goal of a firewall is to block malicious traffic requests and data packages and allow only genuine traffic to a website.
History of Firewalls
Firewalls have been in the market since the late 1980s. They started as packet filters that were set up in networks to analyze packets or bytes transferred between computers. Although packets that filter firewalls are used even today, firewalls have come a long way as the technology has evolved in the last few decades.
1. Gen 1 Virus
Generation 1, Late 1980’s, virus attacks on stand-alone PC’s affected all the businesses and drove anti-virus products.
2. Gen 2 Networks
Generation 2, Mid 1990’s, attacks from the internet affected all the businesses and led to the creation of the firewalls.
3. Gen 3 Applications
Generation 3, Early 2000’s, exploited vulnerabilities in applications that affected many businesses and led to Intrusion Prevention Systems Products (IPS).
4. Gen 4 Payload
Generation 4, Around 2010, the rise of targeted, unknown, evasive, polymorphic attacks affected many businesses and resulted in the invention of anti-bots and sandboxing.
5. Gen 5 Mega
Generation 5, Around 2017, large-scale, multi-vector, mega attacks using advanced attack tools led to the invention of advanced threat prevention solutions.
What do firewalls do?
Firewalls are an integral piece of any software architecture that prevents hosts from having to deal with network protection, taking care of it for them. Next-generation firewalls are focused on blocking malware and application-layer attacks. A next-generation firewall with an IPS reacts quickly to detect and stop external attacks on the whole network.
Additionally, these firewalls can also set policies that help defend your network effectively and carry out a quick assessment to help you detect suspicious activities like viruses and malware and shut it down.
Why do we Need a Firewall?
Firewalls like Next-generation firewalls focus mainly on blocking malware and application-layer attacks. However, with the help of the IPS, these Next-generation firewalls react quickly and seamlessly to detect and combat attacks across the whole network.
Firewalls work based on the set policies that help to protect your network and carry out assessments to detect malware and resolve it.
With a firewall, you can set up your network with policies that allow or block incoming and outgoing traffic.
Eight types of Firewalls
There are eight different types of firewalls based on the general framework and the method with which they operate.
1. Packet-filtering firewalls
Packet filtering firewalls are the most basic and the oldest type of firewall framework. This type of firewall creates a checkpoint at a traffic router or switch. The firewall performs a simple check on the data packets that come through the router-inspection information like destination and origination IP address, packet type, port number, and other information without opening up the packet to inspect its contents. However, if the given information packet does not pass the test/inspection, it is dropped.
A good thing about these firewalls is that they are not resource-intensive. In simple words, they do not have a huge impact on your system’s performance and are very simple to use. However, packet-filtering firewalls are easy to bypass compared to other firewalls that come with stronger inspection abilities.
2. Circuit-level gateways
Another simple type of firewall that easily approves or denies traffic without consuming many computing resources is circuit-level gateways. It works by verifying the transmission control protocol (TCP) handshake. This TCP handshake is designed to ensure the session packet is genuine.
This firewall is resource-efficient but does not check the packet itself. So, if a packet has some virus or malware but has the right TCP handshake, it will pass right through. That is why circuit-level gateways are not enough and effective to protect your business by themselves.
3. Stateful inspection firewalls
Stateful Inspection Firewalls combine both packet inspection technology and TCP handshake verification. In comparison to packet-filtering firewalls and circuit-level firewalls, it is considered an effective firewall that provides more protection against malware and viruses.
Additionally, this firewall also focuses more on computing the resources as well. If compared to other firewalls, this could result in slower packet transfers.
4. Application-level gateways or proxy firewalls
Proxy or application-level gateways firewalls operate at the application layer to filter all the incoming traffic between your network and the traffic source.
These firewalls offer protection via a cloud-based solution or another proxy device. Rather than letting the traffic connect directly, this type of firewall establishes a connection to the source, offers the traffic, and then inspects the incoming data packet.
This check is the same as the stateful inspection firewall because it looks at the packet and the TCP handshake protocol. These proxy firewalls perform deep-layer packet inspection, check the actual contents present in the information packet to make sure there is no virus or malware present in the packet.
However, once the check is over and the information packet is approved to connect to the destination, the proxy sends it off. This creates an additional layer of separation between the client (the system where the packet originated) and the individual devices on your network, offering additional protection for your network.
One major drawback of proxy firewalls is that they slow down your system because of the extra steps in the data packet transfer process.
5. Next-gen firewalls
Many newly-released firewalls are being called next-generation architecture. However, there is not much consensus on what makes a firewall the next-gen.
The common feature of next-generation firewall frameworks includes deep-packet checking, TCP handshake checks, and surface-level packet inspection.
These firewalls also include other services like intrusion prevention systems (IPSs) that automatically stop attacks against your network.
The main issue with next-generation firewalls is that their definition is not defined. Therefore, you should ensure you verify the features such firewalls offer before purchasing them.
6. Software firewalls
Software firewalls are any firewalls that are installed on the local device rather than a separate piece of hardware or a cloud server.
The main advantage of a software server is that it is very efficient for creating defense-in-depth by isolating individual network endpoints from one another.
Maintaining individual firewall software on different devices can be a daunting and time-consuming task. Additionally, not all devices support a single software firewall, which means you need to install different software firewalls to protect every network.
7. Hardware firewalls
Hardware firewalls use a physical appliance similar to a traffic router to intercept data packets and traffic requests before they are connected to the servers. A physical application-based firewall provides perimeter security by intercepting malicious traffic from external networks before it reaches the company’s network.
The major drawback of hardware firewalls is that it bypasses the insider attacks. Additionally, the actual capability of a hardware firewall depends upon the manufacturer.
8. Cloud firewalls
When you use a cloud solution to deliver a firewall, it is known as a cloud firewall or firewall-as-a-service (FaaS). Cloud firewalls are synonymous with proxy firewalls since cloud servers are used in the setup.p.
The main advantage of having a cloud-based firewall is that they are easily scalable depending on the size of the organization. As your needs grow, you can add additional capacity to your cloud server. Cloud servers also excel at perimeter security.
Which firewall is right for your company?
Now that you know the different types of firewalls available, the next question that might come to your mind is, which one is the best firewall architecture for my business?
- The simple packet-filtering firewall or circuit-level gateway offers basic protection and has a minimal performance impact.
- The stateful inspection architecture combines both the packet-filtering and circuit-level gateway abilities and has a larger performance impact.
- A proxy or next-generation firewall offers more robust protection but comes with additional charges but at the same time offers higher performance impact.
The real question is, why use only one?
You need to know that no matter how strong a protection layer is, it will never be enough to protect your business.
To offer better protection, your network should have multiple layers of firewalls. For example, you can have a hardware or a cloud firewall at the perimeter of your network and then an individual software firewall on each of your network assets.
Your network becomes more difficult to crack when you have additional firewalls that provide defense-in-depth and isolate different assets. Therefore, preventing hackers from hacking your sensitive information.
Nevertheless, the firewall you need to use will depend on your network’s capabilities, relevant industry compliance requirements, and your existing resources to manage these firewalls.
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