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FortiClient VPN Credential Prompts: Solving the Persistent Authentication Challenge

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A widespread technical issue affecting FortiClient VPN users across multiple versions has emerged as a significant productivity barrier for organizations relying on secure remote access. The core problem manifests as the VPN client repeatedly prompting for credentials even when users attempt to save their login information, with particular severity in deployments using Azure SAML Single Sign-On (SSO). This persistent authentication challenge spans FortiClient versions 7.2 and 7.4, creating administrative burdens and user frustration while complicating enterprise security deployments.

The Azure SAML SSO Credential Caching Breakdown

A prominent thread in Fortinet's support community details a regression in credential caching functionality specifically affecting Azure SAML SSO integrations starting with FortiClient version 7.2.

According to multiple administrator reports, while FortiClient 7.0 maintains Azure SSO sessions properly without reprompting for credentials, versions 7.2 and 7.4 consistently require reauthentication despite users selecting options to remember credentials and multi-factor authorizations. The connection establishes successfully but fails to preserve the authentication state for subsequent logins.

The External Browser Workaround

Administrators have identified one functional workaround for this Azure SAML issue: enabling the "Use external browser as user-agent for SAML user authentication" option within the VPN connection configuration. This setting appears to restore proper credential caching behavior, suggesting the problem lies in FortiClient's internal browser component in newer versions.

Community Finding: "The only workaround I've found so far that seems to work is the 'Use external browser as user-agent for SAML user authentication' being checked within the connection configuration."

Attempting to use the "Don't show again" option during Microsoft's "Stay signed in" prompt with default settings typically results in a -7200 error, though checking the "Do not modify internal browser cookies" option can prevent this specific error while still requiring full credential entry each time.

Fundamental Configuration Causes and Solutions

Beyond the version-specific Azure SAML issue, several configuration elements commonly cause credential prompting problems across FortiClient deployments.

Certificate-Based Authentication Misconfiguration

For organizations using machine certificate authentication in VPN pre-logon scenarios, the Fortinet administration guide explicitly states that credential prompts should not occur. The solution involves editing the Remote Access profile assigned to the endpoint policy and ensuring that "Prompt for Username" is disabled in the tunnel's Basic Settings.

Save Password Feature Hierarchy

The interdependency of connection features presents another configuration pitfall. According to Fortinet documentation, the "Save Password" functionality serves as the foundation for both "Auto Connect" and "Always Up (Keep Alive)" features. Disabling Save Password automatically deselects both Auto Connect and Always Up, which can lead to unexpected credential prompts if administrators believe these features are active.

Table: FortiClient VPN Feature Dependencies | Feature | Description | Dependency | |-------------|-----------------|----------------| | Save Password | Allows password storage in FortiClient | Foundation feature | | Auto Connect | Automatically connects VPN when FortiClient launches | Requires Save Password enabled | | Always Up | Maintains persistent VPN connection with automatic reconnection | Requires Save Password enabled |

VPN Before Windows Logon Requirements

Implementing VPN Before Logon functionality requires specific Windows configuration beyond FortiClient settings. Administrators must ensure the "Users must enter a user name and password to use this computer" option is enabled via the control userpasswords2 command or netplwiz utility. On Windows 11 systems where this option may not be visible, a registry modification at HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\PasswordLess\Device changing DevicePasswordLessBuildVersion to 0 followed by a restart typically resolves the visibility issue.

Platform-Specific Authentication Challenges

Linux Authentication Looping

Fedora Linux users report a distinct authentication loop where FortiClient returns to the password request after initially attempting connection, particularly with IPSec VPN configurations using pre-shared keys. Unlike the Windows version that progresses to token entry, the Linux client fails to present the secondary authentication prompt, creating an unrecoverable loop. Community suggestions indicate alternative connection methods like NetworkManager-openconnect may provide more reliable 2FA handling for SSL VPNs, though this doesn't support IPSec configurations.

Wrong Credentials Errors and Account Lockouts

Multiple organizations report persistent "Wrong Credentials" errors even when passwords are confirmed correct, often accompanied by Active Directory account lockouts. Community troubleshooting suggests several potential causes:

  • Cached credential issues where FortiClient retains outdated authentication data
  • Hybrid AD environment replication delays causing authentication timing problems
  • RADIUS network policy misconfigurations not properly associating VPN portals with user groups
  • Firewall policy gaps failing to route VPN tunnel interface traffic appropriately

Practical solutions include password resets rather than simple unlocks (addressing potential replication issues), complete FortiClient reinstallations to clear cached credentials, and verification of the complete authentication path from client to domain controller.

Proactive Troubleshooting Methodology

When confronting credential prompt issues, administrators should implement a structured diagnostic approach:

  1. Version Assessment: Determine if the issue correlates with FortiClient 7.2/7.4 specifically and whether Azure SAML SSO is involved
  2. Authentication Type Analysis: Differentiate between certificate-based, SAML, and traditional credential authentication
  3. Feature Configuration Audit: Verify Save Password, Auto Connect, and Always Up settings align with dependencies
  4. Platform-Specific Checks: Review Windows registry settings for VPN Before Logon or Linux authentication handling
  5. Connection Testing: Isolate variables by testing with different networks (including mobile hotspots) to rule out network-level interference

For IPSec VPN connections displaying "IPSec VPN connection is down" errors after credential entry, modifying the Phase 2 DH Group to 14 has resolved issues for some organizations, particularly when business networks may interfere with standard VPN negotiation.

FAQ: FortiClient Credential Prompt Issues

Q1: Why does FortiClient keep asking for credentials with Azure SAML SSO in versions 7.2 and 7.4?

A: This is a known regression from version 7.0. The internal browser component in newer versions fails to properly cache SAML authentication tokens. The most reliable workaround is enabling "Use external browser as user-agent for SAML user authentication" in the connection settings.

Q2: How do I enable automatic VPN connection without credential prompts?

A: Three features must be properly configured: (1) "Save Password" must be enabled, (2) "Auto Connect" can then be enabled (requires Save Password), and (3) for certificate-based authentication, ensure "Prompt for Username" is disabled in the tunnel's Basic Settings.

Q3: Why do I get "Wrong Credentials" errors even with the correct password?

A: This can indicate cached bad credentials in FortiClient, Active Directory replication delays in hybrid environments, or account lockout states not yet reflected across all domain controllers. Try a complete password reset rather than just unlocking the account, and consider reinstalling FortiClient to clear cached credentials.

Q4: What should I check for VPN Before Logon functionality on Windows?

A: Ensure "Users must enter a user name and password to use this computer" is enabled via control userpasswords2. On Windows 11, if this option isn't visible, modify the registry value at HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\PasswordLess\Device\DevicePasswordLessBuildVersion to 0 and restart.

Q5: Are there alternative clients if FortiClient has persistent authentication issues?

A: For SSL VPN connections (not IPSec), some Linux users report better 2FA handling with NetworkManager-openconnect. However, for managed enterprise environments or IPSec requirements, working with Fortinet support or implementing the identified workarounds is generally preferable to maintain compatibility and support.