For about two decades, the corporate VPN was the way remote work happened. An employee opened a client, entered credentials, and the laptop joined the office network from a hotel room or a kitchen table. It was simple, familiar, and well suited to a world in which most applications lived in one data center and most people worked in one building.
That world has thinned out. Applications sit in several clouds, contractors need narrow access, and a compromised laptop on a flat network can reach far more than its owner ever needed. Many organizations are therefore replacing broad network tunnels with zero trust access, which grants connections to specific applications after checking who is asking and from what device. The sections below explain what changes, how to migrate in manageable steps, and which pitfalls deserve attention.
Why VPNs Are Showing Their Age
A traditional VPN extends the network to the user. After authentication, the remote device receives an address on the internal network and can often reach many systems, subject to whatever firewall rules sit inside. The model assumes that anything past the gateway is trustworthy, which made sense when the perimeter was clear.
Several trends strain that assumption. Staff work from personal networks and unmanaged environments. Software-as-a-service applications live outside the data center, so traffic hairpins through the VPN concentrator only to leave again, adding latency. Third parties such as contractors and suppliers receive accounts that grow broader than intended, and old rules accumulate because nobody wants to break something by removing them.
Security consequences follow. A stolen credential or a compromised endpoint gives an attacker a foothold inside the network, and lateral movement becomes the next step. VPN gateways are also exposed to the internet by design, which makes them attractive targets, and vulnerabilities in these appliances have repeatedly been exploited in real attacks. Capacity and licensing add operational friction when many users connect at once.
None of this means VPNs are useless. They remain adequate for some small environments and specific site-to-site links. The point is that their trust model is coarse compared with what modern risk calls for, which is why many teams are looking for something more precise.
What Changes With Zero Trust Access: ZTNA vs. VPN
Zero trust network access, usually shortened to ZTNA, follows the principle described in guidance such as NIST Special Publication 800-207: never grant trust based on network location alone, and verify each request. Instead of placing a user on the network, ZTNA brokers a connection between an authenticated user and a specific application, and nothing else becomes visible by default.
A direct comparison of ZTNA vs. VPN highlights several differences. A VPN grants network-level access, while ZTNA grants application-level access. A VPN usually authenticates once at connection time, while ZTNA can evaluate identity, device health, location, and risk continuously and revoke access when conditions change. A VPN exposes a gateway that accepts inbound connections, while many ZTNA designs use outbound-only connectors, so applications are not directly reachable from the internet.
Policy changes shape as well. Rules express who may use which application under which conditions, such as a managed device with an up-to-date operating system, and not which IP ranges may talk to which subnets. Access for a contractor can be limited to one internal web tool, with nothing else visible. Logs record application-level sessions, which are easier to interpret than raw network flows.
User experience can improve too. Users may open an application without launching a separate client, and traffic to cloud services can go directly there. The comparison of ZTNA vs. VPN is therefore about precision and visibility as much as convenience.
Migration Steps
A migration works best when it proceeds application by application, with the VPN running in parallel until confidence is established. A practical sequence is:
- Inventory applications, including internal web tools, remote desktop, file shares, databases, and legacy systems, with owners and user groups
- Map who needs access to what, using logs from the VPN and identity systems to find real usage
- Clean up identities, groups, and roles so policies can rely on accurate data
- Define device posture requirements, such as managed status, encryption, and patch level
- Choose an architecture and provider that fits the mix of web and non-web applications
- Pilot with a small group and a few low-risk applications, then gather feedback
- Expand in waves, moving higher-risk or higher-traffic applications once policies are proven
- Tighten and retire VPN access gradually, removing broad rules as each application moves
Communication supports each step. Tell users what is changing, why, and where to get help, and provide short guides for the new experience. Keep a rollback path during early waves so that an unexpected problem does not strand people.
When comparing ZTNA vs. VPN performance in the pilot, measure real tasks: login time, application responsiveness, and support tickets. Those numbers help the business case and expose configuration problems before they spread.
Pitfalls to Plan For
Legacy applications cause the most trouble. Some rely on protocols that do not proxy cleanly, require inbound connections from servers to clients, or assume a flat network, such as certain voice, printing, and management tools. Identify these early and decide whether to adapt, isolate, or keep a restricted VPN path for them.
Poor identity hygiene undermines policy. If groups are outdated and shared accounts persist, a fine-grained access model simply encodes the mess. Fix directory data first, and remove shared logins where possible. Strong authentication, ideally phishing-resistant, belongs at the front of the design.
Device posture checks can lock out legitimate users when they are too strict or unreliable. Start in monitoring mode, review which devices would fail and why, and provide a clear route for remediation. Unmanaged and personal devices need a defined policy, such as browser-only access with limited functions.
Other pitfalls include over-ambitious cutovers, policy sprawl as exceptions multiply, and unclear ownership between network, security, and identity teams. Dependence on a single provider's broker raises resilience questions, so understand failure modes and fallback options. Budget for ongoing tuning, since access policies need review as applications and roles change.
Running Zero Trust After the Cutover
Migration does not end when the last tunnel closes. Policies need owners, and access reviews should become routine. Application owners can confirm that listed users still need access, and security teams can look for unused permissions and unusual sessions.
Monitoring changes in character. Application-level logs show which users reached which services and under what conditions, which supports detection of anomalies such as access from a new device or an unusual volume of data retrieved. Feed these logs into existing monitoring and incident response processes so that alerts reach the people who can act.
Metrics keep the program grounded. Useful measures include the share of applications behind ZTNA, the number of remaining VPN users and rules, time to grant and revoke access, support tickets per user, and incidents involving remote access. Report them to leadership with short narratives about what changed and what remains.
Continue refining. Add conditional rules based on risk signals, extend coverage to administrative interfaces and developer tools, and revisit device posture requirements as the fleet changes. Treat the system as a living set of controls, not a one-time project.
End Note
Moving from VPN to zero trust access replaces a coarse, network-wide trust model with precise, continuously checked access to individual applications. The change reduces exposure, limits lateral movement, and gives security teams clearer visibility into who is using what.
Organizations that succeed tend to start with an honest inventory, clean up identity data, pilot with friendly users, and retire VPN access in stages. Patience with legacy systems and careful communication with users matter as much as the technology. A steady, application-by-application migration delivers lasting benefits without unnecessary disruption.
Organizations that migrate in stages, keep the old tunnel only as long as needed, and review access rules regularly tend to see the benefits early: narrower exposure, better visibility, and fewer surprises when a device or account is compromised.
