SSL VPN problems in FortiOS 6.2.0

[atltechpro]

Since updating to 6.2.0 I am having problems with was a very stable SSL VPN.  The VPN stays connected but client sessions disconnects or freezes.  Outlook / Exchange is constantly disconnecting and reconnecting and file shares are experiencing the same type of problem.  The interfaces are running clean and packet captures show that the communications between the client and server just stops and eventually times out.  On the FortiClient side I have tried v5.4 up to current 6.2 with and without DTLS enabled with no joy.  I am aware of the know issue with SSL VPN and RDP #495522 and wondering if it's affecting more than just RDP sessions.  Ideas, anyone else experiencing SSL VPN problems with 6.2?

Thanks

[Galar]

Hi,

We were facing the same issue after upgrading from 6.0.5 to 6.0.9. Applications like SAP or RDP sessions were randomly hanging through FortiClient. Contacted with Fortinet technical support and they confirmed a bug. It will be resolved in 6.0.10 and 6.2.4, but in the meantime, they sent us a private firmware 6.0.9 build 8661.

There is a related known issue. It is about RDP but the engineer recognized that it was also related to other TCP application:

582265: RDP sessions are terminated (disconnect) unexpectedly.

https://docs.fortinet.com/document/fortigate/6.0.9/fortios-release-notes/933609/known-issues

Hope this helps!