SSL VPN occasionally not working


we are using SSL/VPN with AD authentication and OTP for serveral hundreds possible users with aroud 50 users logged in on an average day.

Occasionally we see that the login of a user is not working for no obvious reasons (other users are logged in without any issues). The time of the server and cellphone with the app is in sync and the logfiles on the client and servers show some kind of unspecified authentication error and somethimes a wrong OTP. However everything was correct and the AD account was not locked.

We also see from time to time that the OTP of a user is getting out ouf sync for no reason. After it is resynced again it is working without any issues again.

So far once we saw that a users got stuck in the initialization process of the OTP. This was gone away the next day. Also for no opvious reason and without changing anything. This was not a newly created user and the user has been added to the steering AD group at least one day ago.


Is anybody seeing simular issues?

  • Hallo Bernd,

    What happens if you change "VPN Pool (SSL)" to

    Cheers - Bob

  • In reply to BAlfson:

    Hello Bob, 

    why should I do this? Size? I think we already have a bigger than class c network there (can not check this as I m not currently logged in the company network.

    Best regards,