Threat actors are constantly prowling the perimeters of your computer network in search of a way to infiltrate it for their own destructive reasons. Companies cannot completely lock up their security landscape so tightly that unnecessary traffic is prevented from entering and leaving. A firewall is the intelligent gatekeeper posted at the entrances to your applications, databases and networks. It is responsible for monitoring anything that is attempting to come in or go out, allowing it or preventing it from doing so based on the specifications you have set. It can be software, hardware or cloud-based.

This, however, is a very general definition. Firewall diagrams reveal that there are many different firewall configurations and firewall controls. To protect the security of your organization’s computers and systems from unauthorized outside access, you need to know the types of firewalls in order to determine what best meets your unique needs. Since a robust firewall is your first line of protection against attacks on your networking functions, it is vital that you understand the distinctions among the firewall types.

Firewall types

Packet-Filtering Firewalls

If you want to identify the simplest method of filtering traffic, this layer 3 firewall might be the best solution. These simple FIREWALLS systems are the most traditionally used among corporations. They work by applying a pre-configured set of security rules to all packets coming into or going out of the corporate network. For instance, you could equip this system with a rule that would deny entry to data from specific IP addresses or that uses a particular protocol. When configured with technical rules that are fine-tuned and up-to-date, these traditional network firewalls are both affordable and effective.

Circuit Level Firewalls

A circuit level firewall, also known as a layer 4 firewall, will filter traffic via inspection of the transmission control protocol (TCP) handshake that occurs between packets of information without actually scrutinizing the content of the packets. For that reason, malware can still slip through if these firewalls are the only security gateway services your company uses.

Next-Generations Firewalls

On the surface, next-gen firewalls, sometimes also known as a container firewalls, are similar to their traditional corporate firewall counterparts. However, firewall generations accomplish their goal of protecting against unwanted traffic by looking at the specific contents of each data packet instead of simply examining its protocol, IP addresses and ports. With this added functionality, you can further customize your rules, allowing you to prevent the use of specific applications such as social media and to close off certain capabilities within networks such as the file-sharing portions of Skype. This type of application layer firewall is highly effective in filtering out threats because of its nuts-and-bolts, granular approach. However, this level of detail comes at a price: next gen firewalls are more expensive and slower than other firewall technologies.

Stateful Inspection Firewalls

Building on the tools found in packet-filtering firewalls, these not only employ preset rules to regulate traffic flow but also intelligently look at the content to determine if it should be allowed to go through. Furthermore, this type of gateway firewalls filtering documents session data from start to finish and filters traffic based on port, protocol and origination and destination addresses.

Web Application Level Firewall

These security configurations contain firewall proxy servers that act like sentries between applications that are running on the corporate network and the users who are accessing them from outside. Think of them as a buffer that shields the application from port scans and external snooping while simultaneously analyzing and filtering all data to secure the application against hackers. Especially for organizations that receive significant internet traffic, using this variety of dedicated firewall in conjunction with other different types of firewalls can be the most effective overall solution to prevent breaches.

Database Firewalls

Since databases are the repositories of a great deal of confidential and sensitive client information, they often merit special firewall architecture of their own. If a database firewall is only protecting a single server, it will usually be placed right in front of it. However, these gateway firewalls are put near the network entrance if they are tasked to protect more than one database. Database firewalls work to guard against security threats such as cross-site scripting that is designed specifically to target confidential data.

Unified Threat Management (UTM) Firewalls

Think of these appliances as all-in-one firewall boxes that plug directly into your network and contain many of the features of the other firewalls types we have described. These usually include traditional network firewalls, internet gateway security, intrusion detection, web address blacklisting and other web application and next generation firewall features. UTMs are particularly beneficial for small to medium-sized businesses who want robust network security but may not have the resources or technical know-how to implement it on their own. All of the security features contained in UTMs can be managed from one console, making them effective yet simple to use.

Cloud-based Firewalls

Run remotely by outside providers, cloud-based firewalls provide protection for all of your IT assets. Because they are administered by professionals in very secure locations, these firewalls rarely experience downtime or service interruptions. They are particularly suited to large organizations or businesses with more than one physical location.

Network Segmentation Firewalls

Also known as internal network firewalls, these are designed to control traffic that moves between distinct parts of the network such as websites, departments and databases. In the event of a breach, the infected area can be walled off until the situation is fully addressed.

As you can see, firewalls network security is not a one-size-fits-all proposition. Gateway firewalls are different from each other in order to meet a business on whatever level of need it may possess. For the sake of your clients, your data confidentiality and integrity and the reputation of your enterprise, it is crucial that you carefully examine all of your firewall filters options so that you can choose the solution that offers maximum protection and the features you need at a price you can afford.