The corporate VPN has been the remote access standard for decades. Connect to VPN, and you're "on the network" — access to resources that are only reachable from within the corporate network becomes available. It's a model that made sense when the office and the internal network were the security perimeter.
That model has significant weaknesses in the current environment, and Zero Trust Network Access (ZTNA) offers a materially different approach. Whether it makes sense to replace your VPN depends on where you are and what you're trying to accomplish.
The Problems with Traditional VPN
Full network access. When a user connects to a traditional VPN, they typically get broad access to the internal network — not just to the specific applications they need. A compromised endpoint on VPN can reach many systems beyond the one it was trying to access.
The lateral movement problem. If an attacker steals VPN credentials or compromises an endpoint that's connected to VPN, they have network-level access to everything the VPN segment can reach. This is how initial access turns into full network compromise in many incidents.
No device trust evaluation. Traditional VPN authenticates the user (credentials) but typically doesn't evaluate the health of the device. A personal laptop with malware can connect to VPN as long as the user knows the credentials.
Performance and scalability issues. VPN traffic hairpins through central infrastructure, adding latency and creating capacity constraints at scale. Organizations that scaled remote work rapidly during the pandemic hit these limits.
Legacy authentication. Older VPN infrastructure often doesn't integrate cleanly with modern MFA solutions and identity providers.
What ZTNA Does Differently
Zero Trust Network Access grants access to specific applications rather than network segments, based on verified identity and device posture — before granting any access.
The core difference: VPN says "you're on the network, access what the network allows." ZTNA says "you want to access this specific application — prove who you are, prove your device is healthy, and if both pass, you get access to that application — nothing else."
This addresses several VPN problems:
Application-level access. Compromised ZTNA credentials give access to specific applications, not the broader network. Lateral movement from a ZTNA compromise is significantly constrained.
Continuous device assessment. ZTNA evaluates device posture at connection time (and some solutions, continuously). An unmanaged device, a device with disabled endpoint protection, or a device with outdated patches can be blocked from access or given limited access to a subset of applications.
Identity integration. ZTNA is built to integrate with modern identity providers and enforce strong authentication requirements per application.
Performance. Many ZTNA solutions route traffic optimally rather than hairpinning through central infrastructure, reducing latency for cloud-hosted applications.
The Transition Considerations
Moving from VPN to ZTNA is a meaningful infrastructure project. Key considerations:
Application inventory first. You can't implement ZTNA without knowing which applications remote users need to access and what the access requirements for each are. This inventory is often missing or incomplete.
Not all applications work cleanly with ZTNA. Legacy applications with unusual network requirements, thick-client applications with complex network dependencies, and some development workflows may need special handling or coexistence with VPN.
Change management. Users accustomed to "connect to VPN and everything works" need to understand a new access model. The transition requires communication and support.
Coexistence period. Most organizations run ZTNA and VPN in parallel during transition, moving applications to ZTNA incrementally as testing confirms functionality.
When VPN Still Makes Sense
ZTNA isn't universally better. VPN remains appropriate for:
- Network-level access requirements that ZTNA can't address (some legacy systems, OT network access)
- Site-to-site connectivity (ZTNA is user-to-application; site-to-site VPN serves a different function)
- Organizations where the cost and complexity of ZTNA transition exceed the security benefit
For most organizations with significant remote workforces and cloud-hosted applications, a long-term ZTNA roadmap is the right direction. VPN as a permanent architecture is increasingly difficult to defend.