What is a software firewall?

Firewalls block malicious traffic before it can compromise network assets. The firewall sits between external devices and network assets. It monitors incoming and outgoing traffic, preventing unauthorized access. More advanced firewalls can also inspect traffic to neutralize network security threats.

Software firewalls can be part of effective network security environments. But is firewall software the best way to filter traffic and protect critical assets?

This article will explore how software firewalls work. We will learn about their major features. And we will list a few benefits and potential drawbacks of relying on software firewall solutions.

Software firewall definition

When putting in place a firewall solution, knowing about the different firewall types is essential.

Early network security solutions tended to rely on hardware firewalls. These appliances need separate physical hardware. Software firewalls emerged as a more flexible and lightweight solution.

Software firewalls are traffic-filtering applications. They inspect data packets passing across network boundaries. The firewall allows entry for packets that pass security rules. If not, the data is rejected.

Users install software firewall applications on devices. This could include network servers, individual computers, or even mobile devices. This is the main difference with hardware firewalls, which are themselves devices.

Next-generation firewalls and cloud firewalls are challenging traditional software firewall technology. But software firewalls remain popular and effective in many situations. As a result, it's important to know how software-based web filtering works.

Explanation of software firewall and its functions

The main functions of a software firewall include:

• Applying security rules to screen incoming and outgoing traffic
• Blocking malicious programs and traffic that seek to gain access to network resources
• Allowing authorized users to connect quickly and easily
• Network monitoring to check for threats and gather useful security data
• Reducing the IT workload with lightweight software-based solutions
• Protecting remote devices when hardware firewalls are impractical
  
  

How does firewall software achieve these outcomes?

Firstly, software firewalls form a barrier between the wider internet and business networks. The firewall filters traffic traversing the network boundary according to predefined rules. In their most basic form, software firewalls use packet filtering to detect threats. But advanced versions use stateful inspection to analyze traffic in more depth.

The second key feature of software firewalls is application-based flexibility. Because they are software-based, software firewalls can block specific programs if desired. They can admit individual users to sensitive databases and workloads. And they can control access between applications.

Software firewalls also contribute to network security by controlling access to malicious websites. Users can configure firewall security to block access to dangerous sites. This boosts productivity by blocking sites not related to core workflows. It also helps prevent the transmission of malware via malicious phishing links.

Outgoing filtering is also important. Software firewall technology can monitor traffic leaving business networks. They can detect the transmission of confidential data or files. This helps prevent damaging data breaches, strengthening network security.

Importance of software firewalls in modern-day computing

Software firewalls displaced hardware firewalls for a variety of reasons. Both styles filter network traffic, but software-based firewalls have some important use cases:

• Hardware firewalls generally use a single appliance to protect multiple devices. Users install software firewalls on individual devices.
• Hardware firewalls need complex setup processes and maintenance. They may also be difficult to update as network security threats evolve. Users purchase or download software firewalls as off-the-shelf products. These products should receive regular updates from the provider.
• Hardware firewalls are located in on-premises network centers. Software firewalls can move with devices, making them suitable for remote working.
• Hardware firewall devices cover large networks and can be controlled centrally. Software firewall systems are more granular. They can control device and application access at a finer level of detail.
  
  

Software firewalls suit home users. For example, millions of people use Windows Defender every day on their internet connection. Firewall software also suits businesses that need to secure remote workstations.

Since the Covid-19 pandemic working from home has become routine. Every work-from-home device that connects to network resources needs firewall protection to safeguard data. Filtering a home internet connection is not possible with hardware firewall solutions.

The flexibility of software-based firewalls makes them popular. But it's important to note that they have been challenged by next-generation firewalls and cloud firewall solutions.

Next-generation systems reside in the cloud, close to SaaS applications. They fit neatly with SSO architecture and may be a robust network security option for cloud-dependent organizations.

Features of software firewalls

The core goal of any software firewall is protecting network assets against malicious traffic. Various features work together to make this a reality. These features should be found in most modern firewall software implementations.

Common features of software firewalls

• Packet inspection. All firewalls inspect traffic. Packet filtering checks superficial IP address and port data. Stateful inspection and deep packet inspection leverage state data and packet contents to add more context.
• IP address filtering. Firewalls can filter traffic by allowing approved IP addresses and blocking unknown identities.
• Port filtering. Packet filtering systems gather data about the source and destination ports for data transmissions. Firewalls can allow certain ports and close others.
• Analytics and reporting. Firewalls collect data about access requests. This information can be used in compliance audits and to improve general data security.
• Threat scanning. Advanced software firewalls scan for threats and policy violations via intrusion detection systems. This complements traffic filtering, adding depth to security strategies.
• Security alerts. Firewall software delivers real-time alerts when threats are detected.
• Automated updates. Software firewalls can automatically update threat databases. Firewall protection then reflects state of the art intelligence.
  
  

These features play an important role in protecting network assets. Packet filtering and content inspection analyze traffic crossing the network perimeter. They allow legitimate users easy access. And they can block known threats or apply broad controls to tightly limit access.

Firewalls with access monitoring and reporting capabilities go further. They deliver timely information to IT teams. This information alerts security experts to real-time threats. Organizations neutralize malware or phishing attacks before they cause critical damage.

Auditing features also aid compliance strategies. Data collected by the firewall provides evidence to regulators. Companies can prove that they are protecting customer records and financial information. Audits demonstrate robust security controls – an important part of GDPR, PCI-DSS, and HIPAA compliance.

Another important aspect of software firewall systems is customization. Users can customize most firewall solutions to suit their filtering requirements. IT teams can apply flexible filters to screen IP addresses or DNS requests. If you need to block websites or traffic from a specific country, the firewall will make it easy to do so.

Benefits of using a software firewall

Firewall options include hardware, cloud-based, and next-generation firewalls. But software firewalls deliver many benefits and may be worth considering.

Key benefits of using a software firewall

• Application control. With a software firewall, users can block specific programs more easily. The firewall can set security policies for individual applications. Organizations can keep sensitive data or resources off-limits. Managers can tightly control who gains access.
• Threat segmentation. If you use a hardware firewall, attackers can target a single point of failure. Security teams can distribute software firewalls to all connected devices. If a threat compromises one device, firewalls across the network make it harder to spread throughout the organization.
• Easy installation. Software-based firewalls need no hardware configuration. This is an important difference with hardware firewall solutions. Users install the firewall on individual computers. The operation takes seconds. This is a major advantage for remote workers and home users.
• Cost-effective. Software firewall solutions suit smaller businesses with limited resources. A hardware firewall may be too expensive and complex for small business needs. Installing software on workstations and local devices is a cheaper network security option.

How a software firewall can improve the security posture

Software firewalls play a critical role in securing network infrastructure. They may perform this role more effectively than hardware firewalls or next-generation firewall systems. For instance, software-based firewall systems can improve your security posture in various ways:

• Secure remote working. Many companies allow employees to work from home. Workers may need to use work devices while they travel. In both cases, using software to filter traffic makes sense. Firewall software moves with devices. Firewall protection covers remote connections wherever the user goes.
• Identity management. Firewalls operate alongside IAM systems to filter malicious access requests. The firewall can allow approved IP addresses and block others. This admits employees or authorized third parties. But unknown users will struggle to gain access.
• Threat detection. In their basic form, software-based firewalls employ packet filtering to monitor incoming threats. More advanced solutions inspect packet contents and detect suspicious patterns of behavior. Automated alerts let security teams know when to take action.
• Outgoing data filtering. Software firewalls can also monitor outgoing data. Security teams can set their firewall to block websites that are known launchpads for malicious attacks. Advanced versions can protect data by checking outgoing traffic for high-value information.

How software firewalls can save businesses money

Well-designed firewall systems improve more than an organization's security posture. They also save money for business users. Often, they balance costs and security better than hardware firewall alternatives. There are several reasons why this is the case:

• Off-the-shelf solutions. Software firewall technology is often included with operating systems. For instance, users can simply protect their private network with the free version of Windows Defender. A hardware firewall requires a lengthy and complex implementation process.
• Device-based installation. Software firewalls installed on individual workstations can be very cost-effective. A simple installation is all that's needed. IT teams can deliver security policies centrally to every device. By contrast, hardware appliances are more complex to install and expensive to maintain.
• Robust data protection. Software filters could be an effective data security solution for computer networks with many remote devices. Software travels with the user. Wherever they connect, firewalls filter traffic entering or leaving a user's device. This protects any workloads or data from external attackers.
• Lightweight products for low-priority settings. Sometimes security is less important than speed and cost. In that case, it makes sense to use a free version of firewall products. Users may not enjoy optimal protection. But a free version of software-based firewalls can still filter traffic. It may also allow some access controls for unapproved connections.

How to choose the right software firewall

Firewalls play a critical role in defending any computer network against malware, zero-day attacks, DDoS attacks, and other online threats. Choosing the right firewall is essential, and not all firewall products deliver the same security features.

What to consider when choosing a software firewall

Factors to consider when purchasing firewall technology include:

• Device numbers. How many connected devices will your firewall solution need to defend? If you are protecting a small community of devices, software-based firewalls work well. As networks grow, it becomes harder to ensure network-wide protection. It also becomes more difficult to make sure firewall software is updated. For this reason, larger on-premises networks generally suit hardware firewalls.
• Traffic throughput. IT teams also need to choose a firewall that can handle network traffic volumes. This is not always connected to device numbers. Planners need to know a ballpark figure when choosing firewall solutions. If you choose poorly, the firewall may reach its maximum throughput. This leads to high latency and poor performance.
• Employee location. Are your employees located on-premises or do they work from home? Remote work can suit software firewalls. Consider an NG firewall with cloud protection. This is a better fit for protecting access to SaaS and PaaS platforms. A firewall software filter will deliver basic protection for remote access at a lower cost.
• Centralized management. Security teams must update security policies as organizations and threats evolve. This is hard to achieve with multiple software firewalls. Cloud firewalls provide in-depth centralized management. Or you could cover all local assets with hardware appliances. Centralization improves threat visibility and generally boosts the security posture of larger organizations.
• Cost. Firewall security must fit the budget of your organization. And advanced features may not be affordable. At the lower end of the market, look at free firewall solutions. They may not match the features of stateful firewall models. But free firewall software can still filter traffic at a simple level. That's not enough to protect financial data, but a free firewall may be fine for low-level web browsing.
• Advanced features. At the higher end of the market, firewalls deliver advanced security features. Machine learning, threat intelligence databases, deep packet inspection, and IoT protection may be useful. But they increase bandwidth demands. Extra firewall features come with a cost. Plan the features you need and source a firewall that matches your requirements.
• Complexity. Firewalls need maintenance. But can your organization maintain hardware firewalls across all departments and branch locations? Software or cloud-based firewalls often deliver the same protection with lower maintenance overheads. If your IT team is small, they are probably a better solution.

Compatibility of software firewalls with different computer systems

Compatibility is another critical consideration when deciding whether to use a software firewall. Software firewalls must integrate with operating systems and commonly used apps. They must accommodate the protocols used in data transfers. And they should work well with identity and access management tools.

Software-based firewalls are designed to run on a specific OS such as MacOS, Windows, or Linux. This can cause issues when networks feature many different operating system setups. IT teams can struggle to distribute firewall agents to every endpoint. Gaps may appear due to unprotected devices.

This is another reason why hardware firewalls suit larger on-premises networks. Hardware firewalls are installed alongside routers. The hardware firewall then protects every device connected to that router, regardless of what OS it uses. This eliminates many common compatibility issues.