Performance Issues with EMS FortiVPN Client – Free Client Works Fine

[leo-ehk]

Hello Community,

we have several employees experiencing severe performance issues with the Forti EMS Client 7.2.8, particularly when accessing internal websites via VPN and using applications like SAP GUI. In some cases, connections even drop unexpectedly.

Even after reinstalling the client, the problem persists. However, when switching to the free Forti VPN Client, the issues disappear immediately, and everything runs smoothly.

Our environment:
- In-house EMS Server 7.2.8 with FortiClient 7.2.8
--FortiGate connected via IPv4 only (IPv6 is disabled on WLAN and VPN adapters)
- Only SSL VPN is used; all other VPN options are disabled

Does anyone have an idea? Many thanks in advance!

[AEK]

Hi Leo

Are you using Web filter and/or app filter features? Can you try disable them temporarily just to see if they are causing the issue?

When you day "connections even drop unexpectedly", do you mean the connection to your application or the whole VPN connection?

[leo-ehk]

Hello AEK,

we don't use WebFilter or other things. We use only SSL VPN and disabled all other things. 

Not the VPN Client connection, i mean the connection to our internal applications. For example: Websites, Filesrv and SAP GUI to internal SAP Servers. The VPN connection is running and up.

Thank you"!

[AEK]

Can you try other versions on some test clients, like 7.2.7 and 7.4.3.

[leo-ehk]

Hello AEK,

thanks for your help!

We already tried other versions. Its always the same and the problems are massive. We even tested a rollout on a new notebook and the problems occur again. For example, the client connects to the VPN and the user accesses our ticketing system through the VPN tunnel. The user can open the website and use the ticketing system very slowly. As soon as they create a ticket, the connection is interrupted. We observe the same issue on NTFS File Service and SAP GUI. After install the free Version - The User have a top permonce without problems. If we install the EMS Client - The Problem comes back.

Thank you very much!

[AEK]

Hi Leo

As per my experience with multiple versions of EMS, I don't thing the issue is coming from the registered FCT itself, but probably from somewhere else.

I'd suggest the following:

• Check if both registered and unregistered clients (I mean FCT before registration, NOT the free FCT version) have the same behavior
• Confirm if the traffic of clients with free VPN and clients with licensed FCT are using the same FGT firewall rules. i.e.: they may use different rules if some rules are matching ZTNA tags. You may also check the traffic logs for that

What is the FortiOS version?

[leo-ehk]

Hi AEK,

i will test your suggestions. Thank you!

Could the problem also be related to the IPv6 configuration?

We don't have an IPv6 connection with our Internet provider. The IPv6 adapter configuration needs to be disabled. We also tested the connection via a mobile hotspot, and the issue didn't occur in that case. Forti OS is 7.4.7 Mature 2732.

Leo

[AEK]

Hi Leo

As part of the troubleshooting you can try disable IPv6 in your Windows and try again.

In case it doesn't help, since you said it works fine with mobile hotspot, then it can be related to your ISP, and in that case I have no idea.

[leo-ehk]

Hi AEK,  

IPv6 was just an idea, but we've already disabled IPv6. Perhaps there's something else we can disable on the FortiClient? And yes, we just successfully tested the connection via hotspot. The strange thing is that this is happening to five users already. Is that a problem with the ISP? Alle Users work with a FritzBox Firewall and all have the same ISP. That is strange.

[AEK]

Trying to disable IPv6 is a good idea for test, as I already saw some FCT issues caused by IPv6.

According to your input the root cause may be your ISP. In case you have access to the router they you may disable IPv6 on its WiFi as well.