FortiClient SSL VPN Error: Unable to establish the VPN connection. The VPN server may be unreachable

[techdsmart]

Hi,

I started having issue recently with FortiClient (Windows) from versions 7.0.7 to v 7.2.1.0779.

All my FortiClient are connected to Licensed EMS server (on-prem) and SAML enabled with Azure IdP for VPN login.

SSL VPN fails at 70% or sometimes at 98% with the error: Unable to establish the VPN connection. The VPN server may be unreachable. (-6007)

I have reinstalled different client versions but still same error. Some community posts suggest internet issues but i don't think it is. On the same network, FortiClient v7.2.0.0101 (Android) SSL VPN works with SAML enabled and Windows Add vpn option with FortiClient as provider works well too (Ofcourse no SAML for this)

I have checked logs in Fortinet folder and see following errors under:

FortiVPN_1

[2023-08-15 13:07:54.7483807] [14204:14208] [FortiVPN 1811 info] fortivpn::StateMachine::HandleTunnelDisconnected disconnection reason: 12, ("Failed Unknown")

sslvpndaemon_1

[2023-08-15 13:15:06.5364715] [13644:5388] [sslvpndaemon 1186 info] prevLockdownEnabled=0 lockdownEnabled=0 prevConnectionUp=-1 bConnectionUp=0, ManualConnectionCount=0
[2023-08-15 13:15:06.9218229] [13644:1836] [sslvpndaemon 840 info] SSLVPN_REQ_GET_STATUS
[2023-08-15 13:15:06.9218607] [13644:1836] [sslvpndaemon 1186 info] prevLockdownEnabled=0 lockdownEnabled=0 prevConnectionUp=-1 bConnectionUp=0, ManualConnectionCount=0

sslvpnlib_1

2023-08-13 22:09:47.6328028] [14204:14208] [sslvpnlib 497 debug] FortiSslvpn: CSvlauncherDlg::InitFortiSslvpn() Called.
[2023-08-13 22:09:47.6335424] [14204:14208] [sslvpnlib 497 debug] FortiSslvpn: CSvlauncherDlg::InitFortiSslvpn(): Daemon is running
[2023-08-13 22:09:47.6335739] [14204:14208] [sslvpnlib 497 debug] FortiSslvpn: SslvpnAgent: before connect pipe
[2023-08-13 22:09:47.6335811] [14204:14208] [sslvpnlib 497 debug] FortiSslvpn: SslvpnAgent: before create file
[2023-08-13 22:09:47.6336879] [14204:14208] [sslvpnlib 497 debug] FortiSslvpn: SslvpnAgent: ActiveX connected to SslvpnDaemon
[2023-08-13 22:09:47.6337081] [14204:14208] [sslvpnlib 497 debug] FortiSslvpn: CSvlauncherDlg::InitFortiSslvpn(): SslvpnAgent initialized successfully
[2023-08-14 09:11:29.7876573] [14204:14208] [sslvpnlib 497 debug] FortiSslvpn: CSslvpnBase::SetDisconnectEvent:6415 call DisconnectFortiSslvpn.

[2023-08-14 09:11:29.7876694] [14204:14208] [sslvpnlib 497 debug] FortiSslvpn: CSvlauncherDlg::DisconnectFortiSslvpn() Called.
[2023-08-14 09:11:29.7876765] [14204:14208] [sslvpnlib 497 debug] FortiSslvpn: CSslvpnAgent::DisconnectSslvpn 181
[2023-08-14 09:11:32.1674011] [14204:14208] [sslvpnlib 554 debug] FortiSslvpn: CSslvpnBase::AfterDisconnected is called

[2023-08-14 09:11:32.1674195] [14204:14208] [sslvpnlib 554 debug] FortiSslvpn:
[2023-08-14 09:11:32.1674299] [14204:14208] [sslvpnlib 554 debug] FortiSslvpn: GetWebPage(): URL=/remote/logout -->

[2023-08-14 09:11:32.1674421] [14204:14208] [sslvpnlib 554 debug] FortiSslvpn: ======
[2023-08-14 09:11:32.1674464] [14204:14208] [sslvpnlib 554 debug] FortiSslvpn:
[2023-08-14 09:11:32.1674505] [14204:14208] [sslvpnlib 554 debug] FortiSslvpn:
======
[2023-08-14 09:11:32.1674566] [14204:14208] [sslvpnlib 554 debug] FortiSslvpn: GetWebPage(): bRC=0,CT=(), length=0

 Any ideas on what could be the issue?

[Anthony_E]

Hello,

Thank you for using the Community Forum. I will seek to get you an answer or help. We will reply to this thread with an update as soon as possible.

Thanks,

[Anthony_E]

Hello,

We are still looking for someone to help you.

We will come back to you ASAP.

Regards,

[Anthony_E · Accepted solution]

Hello,

I found this documentation:

https://community.fortinet.com/t5/FortiGate/Technical-Tip-The-VPN-server-may-be-unreachable-20199/ta...

Could you please tell me if it helps?

Regards,

Anthony

[trivero]

Hi Anthony_E

The link that you posted is archived, not going anywhere.

Any idea of an updated link.

Thanks in advance.