Firewall Implementation Checklist: Ensuring a Robust Defense Strategy

In today’s world, cyber crimes increase in rate, frequency, and advancement and this puts all sizes of businesses at high risk. That’s why protecting corporate networks, users and devices has never been this important. Businesses must build solid security strategies, and policies and implement enhanced security solutions. From there they need to maintain and monitor security tools and policies. For network layer security many businesses go for firewall solutions as they have been indispensable and must-have security components for more than 30 years. 

With firewalls, businesses enable robust network security by monitoring traffic, segmenting corporate networks, and preventing unauthorized access. Also, firewalls can and should be integrated with other security solutions to create a comprehensive cybersecurity posture and solid defense against cyber attacks. To get a firewall’s full benefits, businesses must adequately implement firewalls and maintain their health. Firewall misconfigurations can leave corporate networks exploitable and vulnerable to cyber attacks. For this reason, they must be integrated correctly. In this article, we gathered a firewall checklist to help you ensure a robust defense strategy. Before explaining the firewall implementation steps, let’s define firewall solutions and their role in cybersecurity.

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Defining Firewall: Its Role in Cybersecurity

A firewall is a computer network security system that acts as an intermediary and functions as a roadblock between a private network or devices and the worldwide internet. Firewalls are seen as the first layer of defense against cyber attacks and their primary features are monitoring & controlling all incoming and outgoing traffic and preventing unauthorized users from accessing private corporate networks. With firewalls, businesses can control which type of traffic should be permitted to go in and out by setting up firewall rules. These rules can be based on the packet’s source address, packet headers, ports, destination address, domain names, keywords, etc. Simply, Firewall rules can be set for controlling traffic, preventing malicious codes and traffic from infiltrating networks, and restricting access to certain areas & corporate data and malicious content. Also, firewalls can detect incoming illicit traffic and alert IT admins and help businesses prevent cyber attacks like Denial-of-service, social engineering, or malware. There are five types of firewalls and these are Packet Filtering, Circuit Level Firewalls, Application-level (Proxy), Stateful Inspection, and Next-generation firewalls. 

Firewalls alone can’t establish overall protection against advanced cyber threats. That’s why they need to be used along with other security solutions. Firewalls can be a critical part of businesses cyber security postures and they can help businesses create a layered defense against cyber attacks.  

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Key Factors to Consider Before Firewall Implementation

Before implementing firewalls you need to set your firewall objectives and goals. Secondly, you should analyze your company’s needs and determine which type of firewall matches your needs. In the market, there are different types of firewalls available and each has different functionalities, features, and methods, so learning their capabilities and differences can help you choose the best firewall solution in accordance with your needs. Afterward, you must evaluate vendors and consider working with reputable vendors. Then you should examine all of your corporate assets, user groups, devices, and network areas that require firewall protection, and outline a firewall deployment roadmap. 


Firewall Selection: Hardware vs. Software Firewalls

Firewall selection is a crucial step since a firewall should fulfill your business needs and desires.  So, selecting the correct option for your business requires you to understand the different kinds of firewalls and their functions. Today, we will help you to differentiate between hardware and software firewalls, and pick one or both according to the objectives of your strategy. 

Hardware firewalls are physical equipment that separates the network from the Internet. Hardware firewalls can be designed as a computer or even as bigger equipment designated for server rooms.  Before the traffic flows from the internet gateway, it encounters firewalls first and then flows into the network if it is given permission. So, hardware firewalls are integrated into the routers. Because they are installed externally, hardware firewalls take up extra physical space, and configuration isn’t easy. Running independently allows them to be less likely to be attacked. Also, hardware firewall solutions reduce latency and increase bandwidth.  

On the other hand, software firewalls are frameworks run on the system or server. So, they are installed on the devices and systems. While hardware firewalls protect the whole network, software firewalls protect the systems they run on and need to be installed on every system or device on the network. Software firewalls offer easy maintenance and configuration, affordable setup, and high flexibility but consume resources and can slow down the performance of computers.  So, if possible, businesses must implement hardware and software firewalls together in the network.

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Step-by-Step Firewall Implementation Checklist

Step 1. Evaluate needs and set strategy objectives


  • Business size and distribution
  • If your business has in-house management or needs a managed firewall
  • Required type of inspection
  • Business assets, data, and devices that need protection
  • Vulnerabilities, strengths, and weaknesses

Step 2. Pick the right type of firewall

  • Hardware vs. software firewalls or both
  • Pocket firewalls, circuit-level firewalls, packet filtering, stateful or stateless inspection firewall, and NGFW 

Step 3. Secure and configure your firewall properly

Step 4. Implement a firewall policy

Step 5. Test your firewall regularly and update it

Step 6: Monitoring and Maintenance

Rules and Policies: Configuring Your Firewall Correctly

During firewall setup, 5 critical areas need configuration: firewall zones and IP addresses, ACL, ports, logging, and other firewall service features. When setting firewall zones, businesses should segment network assets based on their level of risk and similar functions. Access control lists should be configurated specifically to exact source and destination numbers since they act as firewall rules. That’s why, every ACL must have a “deny all” rule to filter unapproved traffic. Remember to configure your firewall to enable IPS, DHCP server, and NTP server to achieve robust defense. Also, businesses must implement a solid firewall policy in light of correct configurations. 


Testing Your Firewall: Verifying Your Defense Strategy

Besides proper implementation and configuration, penetration testing and vulnerability scanning are essential for an effective firewall. These tests will allow your organization to check if the firewall is working as intended, spot the vulnerable areas in your interface or network, and strengthen weaknesses to mitigate cyber security risks. 


Monitoring and Maintenance: Ensuring Firewall Efficiency Over Time

Correct configuration and firewall penetration testing aren’t enough and aren’t one-time-only practices. Maintaining the integrity of your firewall and monitoring your interface is vital if you want to achieve long time success in robust cybersecurity. By doing maintenance, your organization ensures your firewall stays efficient in all of its operations and functions. This way, you can ensure that all outgoing and incoming traffic are properly regulated, and unauthorized access is strictly blocked. Firewalls must be regularly tested to find and remediate the vulnerabilities within the system. Otherwise, the defense provided by your firewall decreases significantly over time and puts your business in danger of cyber attacks and hackers. 


Case Studies: Successful Firewall Implementation and its Impact

A Finland-based enterprise called VR Group is in the rail industry and operating a high-speed train network. They wanted to combat the challenges of 5G integration, lower bandwidths, lack of offsite management, and average internet speed across the network with NGFW. Senior architect of VR Group, Pasi Louko says “Our costs — both for the project and maintenance — are going down, because we don’t need resources locally — we have centralized everything” after NGFW implementation. NGFW implementation lead them to enhanced capacity, lower head and VPN costs, 200 Mbps data transfer, secured network connectivity, and reduced downtimes. 

A California-based enterprise Adventist Health has 24 facilities, 320 clinics, and 350 locations with 34,000 employees. Inconsistent policies were created across the network due to firewall intricacies which lead to inefficient and time-consuming management.  Migrating to the right firewall allowed them to have better threat protection, unified management, higher operational efficiency, and enhanced firewall management. Also, firewall intricacies were reduced and it saved up 144 hours of downtime, log management, and migrations.

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