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Last updated December 27th, 2023 by Avigdor Book

In the realm of network security, the concept of an Internal Segmentation Firewall (ISFW) is gaining traction as enterprises seek to fortify their internal networks against lateral movement and advanced threats.

An ISFW enforces access control and firewall rules within the data center and also extends its protective reach across routers, VLANs, and subnets. By integrating ISFWs, businesses can enhance cybersecurity, reduce the attack surface, and align with a zero trust model. Let’s delve into the purpose, deployment, and benefits of ISFWs for today’s complex enterprise networks.

Purpose and Deployment of ISFWs

The purpose of an internal segmentation firewall (ISFW) is to add a layer of security within your internal network, essentially breaking down the network into smaller, more manageable and secure segments. This segmentation helps to control who has access to different parts of the network, reducing the likelihood of lateral movement by cyber attackers.

Deploying an ISFW requires careful planning and consideration. It’s not just about setting up barriers; it’s about understanding the flow of your network traffic and ensuring that necessary communications can occur without hindrance while blocking potentially harmful traffic. Think of it as creating a series of checkpoints throughout your internal network, with each checkpoint having its own set of rules and regulations tailored to the specific needs and security requirements of that network segment.

The Difference Between Firewalls and Segmentation

When discussing network segmentation in cybersecurity, it’s critical to understand the difference between traditional perimeter firewalls and segmentation. A perimeter firewall acts as the gatekeeper to your network from the outside world. In contrast, segmentation, and more specifically an ISFW, divides your internal network into separate zones to contain breaches and prevent an attacker from gaining access to the entire network.

Network Segmentation Best Practices

Adopting best practices for enterprise network segmentation is a proactive step towards enhancing your cybersecurity posture. Here are some key strategies:

– Define clear segmentation rules and enforce them consistently across the network.

– Ensure that segmentation policies reflect the criticality and sensitivity of the data within different segments.

– Regularly review and update segmentation rules to adapt to changes in the network architecture or business processes.

The Tufin Orchestration Suite is a powerful tool in implementing these strategies, offering advanced capabilities for designing and managing network segmentation solutions that are tailored to your organization’s specific needs.

Benefits of ISFW and Zero Trust

Deploying an ISFW aligns well with the Zero Trust model, which operates on the principle of “never trust, always verify.” By segmenting the internal network, ISFWs help to enforce this model by ensuring that every request for access is evaluated critically, regardless of the source. This approach reduces the attack surface and mitigates the impact of potential breaches.

Leveraging Technology for Enhanced Security

Modern enterprise networks are complex with a mix of SDN, VPN, VLANs, and endpoints, making centralized firewall management a necessity. Solutions like Fortinet’s FortiGate and Cisco’s range of security products can be integrated into your network, providing robust security controls. However, managing these disparate technologies can be challenging, which is where security policy management solutions come in.

With Tufin, you can enjoy centralized control over your security policies, helping to streamline the management process and maintain a strong security posture. Tufin’s solutions provide a comprehensive view of your network traffic, enabling you to make informed decisions about access controls and segmentation policies.


Adopting an internal segmentation firewall is a significant step towards fortifying your internal network and embracing a Zero Trust security model. By understanding and implementing ISFWs, you can effectively manage your network security, keep pace with advanced threats, and ensure business continuity.

FAQS on Internal Segmentation Firewalls

Q: What is the role of an internal segmentation firewall in enhancing network security?

A: An internal segmentation firewall (ISFW) plays a pivotal role in bolstering network security by controlling internal network traffic. It segments parts of the network to limit lateral movement of threats, thus reducing the attack surface and containing the spread of malware. ISFWs are especially crucial in data center environments where they help to protect sensitive information by enforcing security policies and access control within the internal network. For more details on how segmentation contributes to a robust cybersecurity posture, feel free to read our article on securing your network.

Interested in understanding more about network segmentation and its benefits? Check out our related blog for insights on simplifying network segmentation.

Q: How does an internal segmentation firewall differ from a traditional perimeter firewall?

A: While a traditional perimeter firewall acts as a gatekeeper to control traffic between the internet and the internal network, an internal segmentation firewall (ISFW) provides granular control within the internal network itself. This approach segments the enterprise network into distinct security zones, each with its own set of firewall rules and access controls. Segmentation firewalls are integral to a defense-in-depth strategy, mitigating the risk of cyberattacks spreading across the network. They are a key component in implementing a zero trust model and micro-segmentation strategies. To delve deeper into these concepts, we invite you to explore our article on enterprise network segmentation best practices.

Looking for comprehensive insights into firewall security standards? Our blog on firewall security standards is an excellent resource.

Q: In the context of cybersecurity, what is network segmentation and how does it relate to internal segmentation firewalls?

A: Network segmentation in cybersecurity is the practice of dividing a larger network into smaller, discrete segments or subnets. Each segment can have its own security policies and controls, effectively isolating it from other parts of the network. An internal segmentation firewall (ISFW) enforces this segmentation by controlling the flow of network traffic between segments. This not only enhances security by reducing the attack surface but also improves performance by limiting unnecessary traffic. ISFWs are crucial for protecting against cyber threats and managing access to sensitive areas of the network, such as the data center or customer information. For a deeper dive into network segmentation, you might find our article on simplifying network segmentation quite informative.

Discover the key steps to implementing effective network segmentation by reading our article on enterprise network segmentation best practices.

Wrapping Up

If you’re looking to enhance your cybersecurity framework, consider exploring how Tufin’s solutions can simplify the complex task of securing your network. To see these solutions in action and understand how they can benefit your organization, don’t hesitate to sign up for a Tufin demo.

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