By 
One of the key problems companies encounter when trying to obtain their sensitive data is finding the correct tools for the job. Even for a common tool such as a firewall, many companies might not be able to figure out to how to find the right firewall for their requirements, how to organize those firewalls, or why such firewalls might be important.
What is a Firewall?
It is a type of cybersecurity tool that is used to sieve traffic on a network. Firewalls—which can be software, hardware, or cloud-based—can be used to separate network nodes from outside traffic sources, inner traffic sources, or even particular applications. The key objective of a firewall is to choke malevolent traffic requests and data packets while letting genuine traffic through.
8 Types of Firewalls
Firewalls can be divided into numerous 8 different types:
- Packet-filtering firewalls
- Circuit-level gateways
- Stateful inspection firewalls
- Application-level gateways (a.k.a. proxy firewalls)
- Next-gen firewalls
- Software firewalls
- Hardware firewalls
- Cloud firewalls
How do these firewalls work? And, which ones are the best for your business’ cybersecurity needs?
Packet-Filtering Firewalls
These firewalls, which are the most basic, basically produce a checkpoint at a traffic router or switch. Packet filtering is both an instrument and a technique that is a basic element of network security. It is an instrument because it helps complete a task, whereas it’s a technique because it is a method of completing a task. Packet filtering usually is cheap to implement, but it must be realized that a packet filtering device does not provide the same level of security as an application or proxy firewall. What is particularly good about these firewalls is that they are not very resource-centric, meaning they don’t have an enormous influence on system performance and are comparatively simple. Nevertheless, they’re also moderately easy to sidestep compared to firewalls with much stronger inspection abilities.
Circuit-Level Gateways
As another basic firewall type that is intended to swiftly and effortlessly accept or deny traffic without consuming substantial computing resources, circuit-level gateways work by confirming the transmission control protocol (TCP) handshake. This handshake check is intended to ensure that the session the packet is from is genuine.
While tremendously resource-proficient, these firewalls do not check the packet itself. Therefore, if a packet held malware, but had the correct TCP handshake, it would pass right through. And that’s exactly why these gateways are not sufficient to protect your business on their own.
Stateful Inspection Firewalls
A stateful firewall that traces the working state and features of network connections navigating it. The firewall is arranged to differentiate legitimate network packets for different types of connections. Nevertheless, these firewalls do put more of a burden on computing resources as well, resulting in the slowdown of the transfer of genuine packets compared to the other solutions.
Proxy Firewalls
These firewalls work at the application layer to sieve inbound traffic between your network and the traffic source. Instead of allowing traffic to link directly, the proxy firewall first sets up a link to the source of the traffic and reviews the incoming data packet. They are the safest types of firewalls, but speed and functionality are highly compromised as they can restrict which applications your network can support. There’s only one problem with proxy firewalls, however: they can create substantial slowdown due to the additional steps in the data packet transferal process.
Next-Generation Firewalls
Most of the recently-released firewall products are being hyped as “next-generation” architectures, but there is not as much agreement on what makes a firewall really next-gen.
Some common characteristics of next-gen firewall architectures comprise deep-packet inspection, TCP handshake checks, and surface-level packet review. These firewalls may contain other technologies as well, such as intrusion prevention systems (IPSs) that work to mechanically halt attacks against your network. The problem is that there is no one definition of a next-generation firewall, so it’s significant to confirm what precise capabilities such firewalls have before investing in one.
Software Firewalls
These include any type of firewall that is installed on a local device rather than a discrete piece of hardware. The big advantage of a software firewall is that it’s extremely beneficial for generating defense in depth by separating individual network endpoints from one another. Nevertheless, maintaining individual software firewalls on diverse devices can be problematic and time-consuming.
Hardware Firewalls
These firewalls use a physical appliance that serves in a way similar to a traffic router to interrupt data packets and traffic requests before they’re linked to the network’s servers. Physical appliance-based firewalls like a hardware firewall excel at border security by ensuring malicious traffic from outside the network is interrupted before the company’s network endpoints are highly vulnerable.
The main problem of a hardware-based firewall, though, is that it is often easy for insider attacks to sidestep them. Additionally, the real competences of a hardware firewall may differ depending on the producer.
Cloud Firewalls
These firewalls are software-based, cloud-deployed network devices, produced to halt or alleviate unwelcome access to private networks. As a new technology, cloud firewalls are intended for contemporary business needs, and sit within online application environments.
The major advantage of having cloud-based firewalls is that they are very easy to gauge with your organization. Based on your growing needs, you can add extra capacity to the cloud server to sieve larger traffic loads. Like hardware firewalls, cloud firewalls excel at perimeter security.
Conclusion
No matter how strong, no one protection layer will ever be sufficient to protect your business. We have, above, inspected numerous Internet-oriented firewall designs in a bid to meet security and performance needs of multi tier applications. In all situations, servers hosting application mechanisms were detached from the company’s corporate network used to carry out internal business, as a primary step to separate resources with different security requirements. To firmly control connections between the application’s layers, we looked at hosting tiers of the application on dedicated subnets. By arranging firewalls in succession, we were able to substantially raise the trouble of gaining unauthorized access to sensitive resources from the Internet. All together, each firewall layer augmented the design’s complexity, contributing to the cost of arranging and maintaining the infrastructure, and raising the probability that it will be misconfigured.
