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For years, network security took a fortress approach: keep risks out, protect users and devices inside certain physical boundaries, and automatically trust identities that make it past the gates. This worked when offices were based in a specific location, with networks protected by VPNs, firewalls, and antivirus software.
The era of hybrid work and cloud infrastructure has collapsed the very concept of a fixed network perimeter. In these environments, every user, device, and application must continuously gain the trust of the network, no matter where it lives. This is the defining principle of the Zero Trust model, the new standard for network security that operates under the classic mantra “never trust, always verify.”
The Key Components of Perimeter-Based Protection
Several core components define the perimeter-based model, also known as “castle and moat security.” While most of these approaches are no longer effective in today’s distributed world, some have been modernized and still hold weight. Let’s take a look at some of them:
Firewalls: The perimeter firewall is your network’s gatekeeper, filtering traffic based on rules like IP addresses, domain names, protocols, and ports. It also acts as a main barrier between internal and untrusted networks.
Intrusion Detection & Prevention Systems: An intrusion detection system scans a network for suspicious activity, while the intrusion prevention system takes proactive measures to block these risks in real time. Both systems are typically deployed behind firewalls to stop threats that may be hiding in traffic.
VPN Gateways: VPNs create secure and encrypted pathways for remote users or branch offices to access an internal network. VPNs are familiar and supported by almost all devices, so in today’s cloud-based world, they are still useful but not ideal.
Antivirus Software: If threats bypass the outer layers of network protection, antivirus software detects and eliminates malware on devices within the network. Contrary to the other legacy security tools, antivirus tools are deployed closer to the protected systems and not near the network boundary.
The traditional network perimeter took an entirely different approach to what’s required for modern network security. That’s why most of these tools are fundamentally ineffective in dealing with modern, cloud-based attacks. Given the advanced and sophisticated methods that modern attackers use to penetrate corporate networks, the third-party risks, IT complexity, and high costs of perimeter armor render traditional network security architectures insufficient for modern-day protection.
However, the perimeter-based model set the foundation for today’s adaptive, more granular security controls. The shortcomings of past models exposed why not all network traffic could be trusted by default, and showed vendors how to address the missing links. Although fixed network boundaries have dissipated since the growth of modern, more advanced approaches, the principles remain relevant. In this way, the castle-and-moat approach wasn’t discarded as much as transformed, setting the stage for security architecture suited for today’s digital world.
The Power of Identity-Driven Networking
Lateral movement is a major cyber risk in old and outdated architectures, where authentication often grants comprehensive access to all data, applications, and systems on a network. Without restricting entry to high-privilege assets, once an attacker compromises a network, there is no limit to the damage that could be done. Insider threats and credential leaks are other common dangers of perimeter-based security approaches.
Attackers typically leverage this broad network access, when it’s granted, to move through the network environment in search of sensitive information such as customers’ financial data or other high-value resources. The rise of lateral movement has led to more sophisticated cyberattacks, such as advanced persistent threats.
Zero Trust changes this by introducing an identity-driven approach to access control. Instead of trusting users based on location, this dynamic methodology assigns trust based on verified identity, device health, context, and least privilege principles.
Beyond security, what are some other networking benefits of Zero Trust architecture?
Productivity Gains
Employees can join corporate systems from anywhere and from their own unmanaged devices, as access permissions are no longer restricted to location. Allowing users to directly and only connect to the resources they need improves speed and application responsiveness, supporting productivity and performance gains.
Network Management
Microsegmentation and identity-based policies reduce the attack surface and eliminate network silos created by complex Virtual LANs. Monitoring sprawling networks with multiple security tools layered inside consumes a significant amount of time. With Zero Trust, network teams spend less time on maintenance and monitoring and more time on strategic improvements.
Scalability
In an environment powered by Zero Trust, adding new users or services doesn’t require redesigning the entire architecture, allowing businesses to scale according to demand without IT disruption. Zero Trust networks are not fixed rings; they’re fluid and follow users, devices, and workloads wherever they are. Adding a new site? Simply register the resource with your Zero Trust provider, and apply your existing identity-based policies.
User Experience
Employees and customers alike now demand seamless user experiences from all digital platforms. With Single Sign-On (SSO) and continuous authentication capabilities, Zero Trust networks enable fewer logins, less friction, and quicker movement between apps and systems. Lastly, Zero Trust architectures log each permission request and network interaction, simplifying compliance reporting and audits by removing manual data collection efforts.
With identity serving as the new perimeter, a couple more critical concepts supporting Zero Trust models come into play: identity and access management and role-based access control. Network security’s evolution from static protection to dynamic, context-aware controls is based on the foundation that modern identity and access management has set.
This foundation is supported by role-based access control, which simplifies administration by grouping users into particular roles that have unique permissions to access specific resources and systems. This further narrows down the granular control of identity-driven network access.
Conclusion
In essence, identity, context, and continuous verification define today’s network perimeter and who is allowed past it. The rise and fall of perimeter-based approaches reflect the consistent, rapid change in the modern technology landscape and simply outline why staying up-to-date with the latest innovations is critical. While a hybrid reality exists—where traditional models can be blended with modern strategies—it’s clear that the future of networking will be protected by zero trust, identity-driven architecture.
