A firewall is a cornerstone of a comprehensive network security approach. These software and hardware based tools keep unwanted traffic out of a network by introducing a barrier between safe network traffic and unvetted outside traffic from any number of endpoints.
Firewalls are quite common among enterprise network security teams. According to eWEEK, a full 94% of companies who responded to a network security survey consider firewalls a critical part of IT infrastructure.
There are nine main categories of firewalls:
- Proxy firewalls prevent direct connection from an outside computer and are often tied to specific applications
- Packet filtering firewalls provide protection at the router level, checking the source and destination IPs of incoming traffic
- Circuit level gateways check the “TCP handshake” to ensure packets are arising from legitimate sources
- Stateful inspection firewalls combine circuit level and packet filter firewalls functions
- Software firewalls require no additional hardware but are often supplemented with additional cybersecurity protections or used in conjunction with hardware firewalls
- Hardware firewalls filter data packets before they reach servers, but are more vulnerable to insider attacks
- Next-generation firewalls often include advanced technology like AI-enhanced cybersecurity feature
- Network address translation (NAT) firewalls only accept inbound traffic allowed by a device on the network
- Virtual firewalls (or cloud-based firewalls) monitor networks that operate in the cloud and are part of the net-generation firewall category
Organizations today typically use next-generation firewalls or combinations of legacy and upgraded firewall protections of various types. Some organizations opt to partner with network security companies that offer Firewall-as-a-Service (FWaaS), an option that involves third-party, remote firewall management.
See below to learn about why firewalls are important and how they can reduce and often, eliminate, specific cybersecurity threats.
Why a firewall is important
Firewalls are must-have network security tools for several key reasons, including network security and other data management considerations. Here are several benefits of firewall protection.
- Cybersecurity. Firewalls are part of virtually every cybersecurity approach. They help to prevent bad actors from reaching valuable data assets and damaging or destroying network architecture. In many ways, firewalls are the iron gate between organizations and the outside world.
- Network traffic monitoring. Firewalls monitor traffic flowing to and from endpoints located throughout enterprise networks, alerting security teams to potential threats. Typical firewalls are part of rules-based systems that compare network traffic requests to predetermined rules and filters, making determinations on which data to allow into the network. Security teams can use data collected by firewall network traffic monitoring to refine those rules over time.
- Blocking restricted content. Organizations can use firewalls to block specific types of content from being accessed by network users, including adult-oriented content or content that uses higher levels of bandwidth like streaming video and music.
- Outgoing data traffic control. Threats that originate inside an organization can include data being sent from an enterprise network to outside entities. A firewall can flag this kind of behavior and completely block specific data types or specified amounts of data from leaving the network environment.
- Privacy enhancement. Firewalls help protect organizational and customer data — as such, they are often integral in establishing an overarching enterprise data privacy security structure. Firewalls can help organizations meet the requirements of various data privacy regulations such as the GDPR and CCPA. Also, many end users and customers seek out companies that promise to protect their data, making a strong firewall approach a good selling point.
- Preventing general data loss. Even data that isn’t protected by data privacy regulations can be vitally important to running an organization. Firewall protection can be extended to cover any type of data that flows across an enterprise network.
- Network security agility. As organizations scale, it’s important that network security scales, too. Modern firewalls can expand to cover endpoints, additional servers, and other network hardware and virtual connections as they are added to a network.
- Non-security related data analysis. Firewalls are primarily intended as network security protection, but they handle significant amounts of “good” network traffic, as well. Traffic data sourced by firewalls can be used alongside other data analysis tools to gain a clearer picture of user behavior, business operations, and even marketing effectiveness.
What cyber threats does a firewall defend against?
Firewalls can thwart cyber criminals attempting to attack networks in several specific ways.
- Viruses. Protecting networks from viruses is one of the key functions of a firewall because viruses can rapidly infiltrate and damage enterprise networks. Every day, hundreds of thousands of new viruses emerge. Firewalls equipped with antivirus protection monitor the endpoints where many of these threats attempt to pass through.
- Hacking. Hackers often attempt to breach networks through endpoints, so having firewall protection can help to stop them. Once inside a network, hackers can rapidly access data, email, proprietary information, banking credentials, and more. While persistent hackers may be able to break through weaker firewalls, most hackers will move on to an easier target when they encounter a well-established modern firewall.
- Spyware and malware. Similar to the way viruses can infect networks, spyware and malware can spread throughout systems and wreak havoc. Once installed, spyware and malware can lie dormant in a system for months or even years before being deployed remotely by a bad actor. This type of attack has been on the rise alongside the rise in the number of endpoints from connected IoT devices like sensors and field communication devices, making firewall protection all the more important.
- Phishing. While a firewall can’t truly prevent phishing attacks from happening (typically, these attacks originate via email or by phone versus a data breach), having a firewall as part of a comprehensive security posture does decrease the likelihood that an outsider can gain network access and uncover data to use in phishing attacks, such as organizational charts, accounting procedures, and proprietary information about products.
Without the benefit of firewall protection, enterprises sit vulnerable to attacks originating outside and inside busy networks. As the number of endpoints increase during times of company growth or with the addition of connected IoT devices, having a firewall solution capable of scaling is an important consideration. Today, modern enterprises tend to look to next-generation firewall technology to meet the challenges posed by increasingly skilled cybercriminals. Firewalls have been an integral part of network security for many years, a fact likely to remain true for years to come.