A firewall is a cybersecurity tool on your network’s perimeter that monitors incoming and outgoing network traffic. It stops unauthorized traffic from accessing your private business systems, blocking malicious users and software.
Firewalls most commonly come in hardware form, but can also come as software and cloud services.
What do Firewalls do and Why Are They Important?
Firewalls work as gatekeepers to your business network. They monitor when users attempt to access your system and lockdown unwanted traffic or unrecognized sources.
A firewall blocks most malicious entities at the perimeter before they even get close to your workstations, databases, or servers.
To visualize it simply, think of firewalls as a filter between your internal network devices and the outside internet. Malware and virus protection in case of intrusions from inside your networks are also built into many firewalls.
Now for a more technical and thorough explanation. A firewall, once installed, creates a border between external networks and your business’s network. This border is inserted inline and across your network connection.
It inspects all packets that go in and out of the protected business network. As the firewall does its inspection, it utilizes a series of pre-configured rules to differentiate benign packets and malicious packets that pose a threat to your systems.
What do packets contain? Data and meta-information about that data such as its source. The firewall takes this information and determines whether a given packet matches its preconfigured allow rule sets.
If it doesn’t, it blocks that packet from getting into your business’s network.
The reason firewalls are critical is that, in many ways, they are the foundation of network security. They first emerged during the dawning years of the internet and have, since then, become standard in most devices.
What are the Types of Firewalls?
The different types of firewalls can be divided into categories based on their structure and method of operation. There are pros and cons to each firewall type, which we’ll also touch on in this section.
Hardware firewalls come in the form of a dedicated physical appliance. This firewall type is excellent at maintaining perimeter security, which keeps out any malicious traffic that might be trying to break into your network.
These firewalls are similar to a traffic router that protects your network by intercepting data packets and traffic requests prior to connecting to your servers.
- The firewall is a separate device that’s specifically made to function as a firewall.
- It’s optimized for performance and security.
- Consistently updated for security on a regular basis, maintaining the latest virus protection, and installing security patches.
- Hardware firewalls can sometimes be more costly than their software and cloud counterparts.
- If your hardware firewall fails, the whole network goes down. There are ways around it, such as High Availability (HA). HA is where you have a redundant firewall, so the other automatically takes over if one fails.
Software firewalls are installed on a local device and run on existing workstations and/or servers rather than on a dedicated hardware piece.
- Can be run on your existing company workstations and servers, so there’s no need to purchase additional hardware.
- Ease of use.
- Software firewalls have limited functionality.
- They tend to take up a lot of space in your system.
- Will degrade the performance of whatever workstation or server it’s installed on.
Cloud firewalls are delivered via the cloud. It’s also sometimes known as firewall-as-a-service (FaaS). Because of the nature of the cloud, these firewall types are easy to scale with your business.
Technically, there are two types of cloud firewalls: those that protect your infrastructure and servers (Type A) and those that protect your business’s network and users (Type B). The “type A and B” terminology is just something we created to differentiate cloud firewall types.
Type A firewalls are designed to use your business’s servers to run a virtual data center as an infrastructure-as-a-service (Iaas) model. The actual firewall application runs on the virtual server to protect in-and-out traffic between the cloud applications.
Type B firewalls, in contrast, often come as stand-alone products or services that aim to protect your network and users. It’s similar to having a local firewall appliance, except it’s run on the cloud. This is the type that’s frequently known as FaaS.
- Some cloud firewalls are capable of protecting your entire cloud infrastructure. They can even protect your cloud servers from other servers. This is useful in the event of an insider or attack or when an outside attack successfully corrupts one of your servers, as the cloud firewall can isolate those servers and protect the greater network.
- Certain types of cloud firewalls are connected to workstations.
Next-Generation Firewalls (NGFW)
Gartner defines next-generation firewalls as “deep-packet inspection firewalls that move beyond port/protocol inspection and blocking to add application-level inspection, intrusion prevention, and bringing intelligence from outside the firewall.”
A great example of a next-generation firewall is the Sophos XG which, among its other useful features, synchronizes your endpoint and firewall security in real-time.
Generally, NGFWs are more feature-rich, and they combine many of the features that traditional firewalls are known for with the ability to conduct antivirus and malware scanning.
Unlike traditional firewalls, NGFWs can filter packets based on applications by using a signature-based IPS to distinguish between safe and malicious applications. They’re also the go-to device for SMBs, especially in office environments.
Difference Between NGFWs and Traditional Firewalls
NGFWs combine the standard features that come with traditional firewalls with the features mentioned below.
- Packet-filtering firewalls — Ensures that incoming and outgoing packets are properly inspected before being granted access.
- Circuit-level gateways — provides User Datagram Protocol (UDP) and Transmission Control Protocol (TCP) connection security. Monitors TCP data packet handshakes to inspect incoming traffic without consuming large amounts of time or resources.
- Stateful inspection firewalls — Can identify the operating state of packets as they’re attempting to gain access to your network, so it knows when they’re malicious or safe and can respond accordingly.
- Application-level gateways (a.k.a. proxy firewalls) — Detects and blocks attacks that would otherwise go unnoticed, such as those attacked to HTTP request strings.
- SSL packet inspection — Prevents the transmission of malware through encrypted connections.
- Reporting — This allows you to customize your reports to understand your network's health and safety, identify applications that are at risk, and visualize CPU and memory usage.
- Anti-malware/Anti-virus — Synchronizes your firewall and endpoint security to protect against malware, viruses, and other more sophisticated cyberattacks.
- Site to site VPN — Can securely connect different workstations to a central office, granting company-wide access to a larger corporate network.
What are the core benefits of using next-generation firewalls?
- Reach prevention and advanced security — Obviously, the primary benefit of utilizing a next-generation firewall is to prevent breaches in your organization’s security. But it also has advanced capabilities that can quickly detect and isolate any malicious entities that just so happen to by-pass your front-line defenses.
- Comprehensive network visibility — Network visibility is critical to proper network security. A good next-generation firewall should give you a clear view of threat activity across users, hosts, networks, and your company devices. If a threat occurs, this benefit would, among other things, allow you to find out where a threat originated, its travel, and its current position.
- Flexible management and deployment options — Your next-generation firewall can be configured to meet the specific unique requirements of your business. Deployment can be on-premise or on the cloud, you can choose from a variety of throughput speeds, and to access different features, you need only turn on different subscriptions.
- Fastest time to detection — Threats are detected within seconds, and you can customize alerts to prioritize certain threats over others.
- Automation and product integrations — You can integrate your NGFW with different tools from your vendor, and automation enables the sharing of all kinds of information relevant to your network security.
Are There Any Vulnerabilities with Firewalls?
The biggest vulnerability to your network is not having a firewall at all, so for all intents and purposes, it’s always better to have one than to be completely open to attack.
As with other forms of security, if your firewall isn’t properly maintained, hackers and other malicious entities may find ways to breach your systems
Remember to keep your firewall updated with the latest security—even better to have it managed properly by a competent IT team or your managed service provider (MSP).
That being said, the less advanced your firewall is, the more vulnerable it is to higher-level attacks, especially if your firewall doesn’t use DPI to investigate data packets fully. Less advanced firewalls tend to get hit harder by distributed denial of service (DDoS) attacks.
These types of attacks are forceful but straightforward, bombarding your network with large amounts of traffic in an attempt to overload and overextend its security and resources.
Although next-generation firewalls can help mitigate these attacks and more, the evolving cyberthreat landscape will always create new challenges that will need to be faced.
One could argue that even firewalls are susceptible to lateral insider attacks, but this simply reinforces the importance of having an advanced firewall that can isolate compromised servers and protect your system as a whole.
Keep in mind that merely having a firewall is not the end-all-be-all of your network security. It’s an essential component of your IT and network security. Still, as a tool, it doesn’t replace the necessity for you to remain vigilant about other threats, your endpoints, and other IT assets.
Firewalls won’t replace the need for your business to have solid policies and protocols in place for data protection, data recovery, business continuity and disaster recovery, and other important areas related to data security.
The Future of Firewalls
The rise of next-generation firewalls has in fact been the biggest change in the evolution of this type of security, as with all innovative technologies, they will only continue to improve as they adapt to new and increasing threats.
Perhaps the most significant change to look forward to is the increase in automation and intelligence in the NGFWs, which will further improve their ability to detect threats and mitigate the damage any breaches cause to your systems.
- What is a firewall? – A firewall is a cybersecurity tool on your network perimeter. It monitors incoming and outgoing traffic through your network and stops unauthorized traffic from gaining access to your sensitive business data. It also blocks malicious users and malicious software.
- What do firewalls do? – Firewalls act as gatekeepers to your private business network. They monitor when users attempt to get into your system and lock down any unwanted traffic or unrecognized sources, which could be dangerous. Ideally, firewalls block malicious entities at the perimeter of your network before they get close to your workstation, endpoints, or servers.
- Why are firewalls important? – Without a firewall, your network security is bare and open for attack from any of the numerous cybersecurity threats that are ever-present in today’s internet-driven world. They’re the foundation of your network security, and as such, they’re typically standard on most devices.
- What are the types of firewalls? – The types of firewalls are divided into categories based on their method of operation and their structure, and application.
- Hardware firewalls come in the form of physical appliances. They’re great for perimeter defense but can often be more costly than firewalls over the cloud or via software.
- Software firewalls are installed on a local device or can run on existing workstations/servers. They’re typically easy to use but can have limited functionality and take up a lot of space in your system.
- Cloud firewalls can be split into two types: those that focus on protecting your business’s servers and infrastructure, and those that focus on protecting your network and users. Both are delivered via the cloud.
- Next-generation firewalls (NGFWs) – These are deep-packet inspection firewalls that are the tip of the spear in network security. They move beyond port/protocol inspection and blocking to additionally provide application-level inspection, intrusion prevention, and utilize intelligence and automation.
- NGFW features – The features of NGFWs include packet-filtering firewalls, circuit-level gateways, stateful inspection firewalls, application-level gateways, SSL packet inspection, intelligence visualized reporting, anti-malware/anti-virus, and site to site VPN.
- Core benefits of NGFWs – Reach prevention and advanced security, comprehensive network visibility, flexible management and deployment options, fastest time to detection, and automation/product integrations.
- Firewall vulnerabilities – The biggest vulnerability of firewalls come not from the tools themselves but from improper care of said tools. Firewalls should be updated and maintained by those who have a proper understanding of firewalls, either your IT team or your MSP. Less advanced firewalls are obviously more vulnerable to sophisticated attacks compared to advanced firewalls like NGFWs.
Prioritize Your Business's Network Security
As we’ve mentioned earlier in this article, the most certain way to keep your business’s network secure is to use firewalls. The more sophisticated the firewall, the more secure your private business systems will be.
We recommend getting a next-generation firewall like the Sophos XG, but unless you have members on your team who know how to properly maintain and make use of its vast array of features, you won’t be making the most out of the amazing tool.
Instead of dealing with the headache and costs that come with training new or current employees to manage your network security, why not hand the task over to an MSP like Commprise?
Our Managed Security Services is ready to provide your business with the technologies, insight, and oversight that your organization needs to stay ahead in the modern business landscape.
Of course, your network security isn’t merely a technological problem, it’s a people problem, as well.
Not only will we make sure your next-generation firewall is up to date to protect against the new threats, but we’ll also work with your team to keep them up to speed on the security best practices and provide comprehensive security awareness training.