OpenVPN vs. Modern WireGuard® Architecture
See how Defguard's WireGuard-based solution compares to legacy OpenVPN. Select a topic to explore the differences.
OpenVPN Performance
OpenVPN runs in userspace, requiring data to pass between kernel and application space for every packet. This creates significant overhead.
- Runs in userspace (slow context switching)
- 100,000+ lines of code to process
- Multi-second connection establishment
- Drops connection on network changes
Defguard + WireGuard® Performance
WireGuard operates directly in the kernel with a minimal, audited codebase. Packets never leave kernel space during encryption.
- Runs in kernel space (zero context switching)
- ~4,000 lines of auditable code
- Sub-100ms connection establishment
- Seamless roaming between networks
OpenVPN Security Model
OpenVPN uses legacy TLS/SSL with configurable cipher suites, creating complexity and potential misconfiguration risks.
- Multiple cipher options (easy to misconfigure)
- Complex certificate management
- Large attack surface (100k+ LOC)
- Stateful connections (vulnerable to attacks)
Defguard Security Model
WireGuard uses modern, fixed cryptographic primitives with no configuration options—eliminating misconfiguration vulnerabilities.
- Fixed modern cryptography (ChaCha20, Curve25519)
- Simple key exchange (no PKI complexity)
- Minimal attack surface (~4k LOC)
- Stateless design (cryptokey routing)
OpenVPN Authentication
OpenVPN's MFA is typically bolt-on, authenticating only at login time. Once connected, the tunnel stays open.
- Login-time 2FA only
- Requires third-party plugins
- Certificate + password combo
- No per-connection reauthentication
Defguard True MFA
Defguard implements protocol-level MFA. Every connection attempt can require fresh authentication with multiple factors.
- Per-connection MFA enforcement
- Biometric auth via mobile device
- SSO integration (Okta, Entra ID, Google)
- Session-based pre-shared keys
OpenVPN Management
OpenVPN Access Server provides basic management, but advanced features require complex configuration or third-party tools.
- Manual client configuration distribution
- Limited SSO integration
- No real-time config sync
- Basic user management UI
Defguard Enterprise Management
Defguard provides comprehensive management features designed for enterprise-scale deployments.
- Zero-touch enrollment at scale
- Pre-logon VPN for Active Directory
- Real-time configuration sync
- Built-in ACLs and firewall management
- Full audit trail with SIEM export
- REST API and webhooks
OpenVPN Codebase
OpenVPN's large C codebase has accumulated technical debt over 20+ years, making security audits challenging.
- 100,000+ lines of C code
- Memory safety vulnerabilities possible
- Complex dependency chain
- Difficult to audit comprehensively
Defguard Codebase
Defguard is written entirely in Rust, eliminating entire classes of vulnerabilities at compile time.
- Memory-safe by design (Rust)
- WireGuard: ~4,000 audited lines
- Core open-source (Apache 2.0)
- Public penetration test reports
- Reproducible builds
Why Companies Switch to Defguard
Organizations replace OpenVPN Access Server with Defguard for three key reasons.
Secure Architecture
Multiple VPN Networks Support
User and Device Management
Enterprise VPN Features Missing from OpenVPN
Defguard includes enterprise capabilities that OpenVPN Access Server doesn't offer—making large-scale VPN deployments manageable.
Zero-Touch Enrollment
Pre-logon VPN for Active Directory and LDAP
Biometric MFA
OpenVPN Access Server vs. Defguard: Full Feature Comparison
A detailed comparison showing why enterprises are replacing OpenVPN with WireGuard-based solutions like Defguard.
| Feature | Defguard | OpenVPN Access Server |
|---|---|---|
| Automated and real time configuration | ✔️ | ❌ Each configuration change requires manual server restart |
| SSO | Internal SSO, External SSO, LDAP/Active Directory | Internal SSO, Radius, LDAP, SAML |
| Internal SSO | ✔️ Full OpenID SSO with possibility of integration of external apps to login with Defguard | ❌ |
| MFA with Authenticator codes | ✔️ | ✔️ |
| MFA with Email codes | ✔️ | ❌ |
| MFA with Mobile Biometry | ✔️ | ❌ |
| VPN Access based on Groups | ✔️ | ✔️ |
| Multiple VPN networks | ✔️ Supporting IPv4 & IPv6 multiple VPN networks | ❌ Only one IPv4 VPN network |
| Support for IPv6 | ✔️ | ❌ Only IPv4 VPN network |
| Static IP per device | ✔️ (from version 2.0) | ❌ Only static IP per user |
| Secure Architecture | ✔️ Separated components with control plane (business logic and connection management) separated from Internet (only accessible from Intranet/VPN) | ❌ All services are bundled the user and admin pages are bundled providing single point of failure and broad attach surface |
| Multiple VPN location support | ✔️ Single control plane for all VPN locations with multiple gateways for each location | ❌ Each location requires dedicated instance of OpenVPN-AS with multiple control planes |
| Per VPN location different multi-factor configuration | ✔️ Each VPN location Internal/External SSO MFA | ❌ Only one VPN location |
| Support For User Multiple Devices | ✔️ - User can easily manage their devices, name/identify them and automatically configure them with one-click or QR Codes - Administrators can easily see users and what user devices are connected or offline and their configurations, client version, operating system | ❌ - There are no devices in OpenVPN AS - there are profiles, when user configures the same profile on multiple devices they can not be connected at the same time Admins only see users connected with no information about the device, system, version, ... |
| Email based configuration sharing | ✔️ | ❌ |
| Secure Enrollment | ✔️ - Dedicated and separated secure stateless interface for secure remote user enrollment/client configuration | ❌ - User portal with profiles part of the OpenVPN AS solution running on the same machine |
| One click Desktop Client configuration | ✔️ | ❌ User must download and import a profile |
| Automated Mobile Client configuration | ✔️ With QR Code | ❌ - User must download and import a profile - Alternatively enter server URL manually and authenticate to download and import the profile |
| Real time & secure configuration synchronization for devices | ✔️ - Dedicated and separated secure stateless interface for secure remote user enrollment/client configuration | ❌ Profiles must be updated / imported manually |
| Network Devices Support | ✔️ Automated configuration provisioning and real time updates | ~ OpenVPN command line can be manually configured and run |
| Linux Desktop Client with MFA | ✔️ | ❌ |
| Split tunnel control | ✔️ - Each user can define connection type in client (full or split-tunnel) | ~ Global Split Tunnel Definition with no possibility to select in the client |
| Firewall based Access Control | ✔️ Full firewall management for Linux, *BSD/OPNSense | ❌ No firewall management only simple ACLs |
| Detailed Dashboard and statistics for VPN connections | ✔️ Users, Devices detailed stats with information about client version, operating system, etc. | ❌ Only activity log |
| Secure technology | ✔️ - Rust based Segmentation & isolation | ❌ Python based UI No segmentation and isolation |
| Detailed Activity log | ✔️ | ✔️ |
| SIEM system integration | ✔️ | ❌ |
| SMTP notifications | ✔️ | ❌ |
| Kubernetes Deployment | ✔️ | ❌ |
| Terraform Deployment | ✔️ | ❌ |
| Web-hook support | ✔️ | ❌ |
Ready to Leave OpenVPN Behind?
OpenVPN was revolutionary in its time, but the world has moved on. WireGuard represents the next generation of VPN technology, and Defguard makes it enterprise-ready with the management features, security controls, and deployment options your organization needs.
Join the organizations that have already made the switch to faster, more secure, and easier-to-manage VPN infrastructure.
Trusted by Organizations Worldwide
Companies have already made the switch from legacy VPNs to Defguard's modern architecture.
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How to Migrate from OpenVPN to WireGuard
Moving from OpenVPN to Defguard doesn't require a forklift upgrade. Follow this step-by-step OpenVPN migration guide for zero downtime.
Deploy Defguard Alongside OpenVPN
Install Defguard on your infrastructure using Docker, Kubernetes, or our one-line install script. Both VPN solutions can run in parallel.
Configure SSO & User Sync
Connect Defguard to your identity provider (Entra ID, Okta, Google, LDAP). Users are automatically provisioned—no manual account creation.
Pilot with Power Users
Roll out Defguard clients to a pilot group. They'll immediately notice the performance improvement and seamless reconnections.
Enterprise Rollout
Use zero-touch enrollment to deploy to all users via Intune, GPO, or your MDM. Decommission OpenVPN when ready.
OpenVPN Migration FAQ
How much faster is WireGuard compared to OpenVPN?
WireGuard is significantly faster than OpenVPN—typically 3x or more in real-world conditions. This is because WireGuard operates at the kernel level with only ~4,000 lines of code, while OpenVPN runs in userspace with over 100,000 lines. WireGuard's stateless design also enables instant connections (<100ms) versus OpenVPN's multi-second handshakes.
Can I migrate from OpenVPN Access Server to Defguard?
Yes. Defguard is designed as a complete replacement for OpenVPN Access Server. It provides all enterprise features including user management, SSO integration, MFA, and centralized administration—but with the performance benefits of WireGuard. Our documentation includes step-by-step migration guides.
Does Defguard support the same authentication methods as OpenVPN?
Defguard supports more authentication options than OpenVPN. In addition to TOTP and certificate-based auth, Defguard offers biometric MFA (using mobile device biometrics for desktop authentication) and native SSO integration with providers like Microsoft Entra ID, Google Workspace, Okta, and JumpCloud.
How does Defguard handle network changes compared to OpenVPN?
WireGuard handles network changes (like switching from Wi-Fi to cellular) seamlessly without dropping connections. OpenVPN typically loses the connection during network transitions and requires reconnection. This makes Defguard ideal for mobile workers and users who frequently change networks.
Is Defguard open-source like OpenVPN?
Defguard's core components are open-source under the Apache 2.0 license, including the server (Core), gateway, and clients. Some enterprise features require a license. All core code is fully auditable, and we publish public penetration testing reports.
Can I deploy Defguard alongside my existing OpenVPN setup?
Absolutely. Many organizations run Defguard in parallel with their existing OpenVPN infrastructure during migration. You can gradually move users to Defguard while keeping OpenVPN operational, ensuring zero downtime during the transition.
What enterprise features does Defguard offer that OpenVPN doesn't?
Defguard includes features not available in standard OpenVPN: true protocol-level MFA (not just login-time auth), biometric authentication via mobile, zero-touch enrollment at scale, pre-logon VPN for Active Directory, real-time configuration sync to all clients, built-in Access Control Lists with firewall management, and comprehensive audit logging with SIEM integration.