Computer loses Network Connection after Check Point Mobile VPN connects successfully

[sobife]

Hello everyone,

I’m experiencing an issue with the Checkpoint Mobile Client on two different devices (a virtual machine and a notebook), where there is no data flow over the VPN tunnel after the connection is successfully established. The connection is initiated but breaks shortly after because no data can be sent or received through the tunnel. Here are the details:

• Device 1 (Virtual Machine):
  Windows 11 24H2 is running in VirtualBox (Host: Windows 10). In NAT mode, the VPN tunnel works perfectly. However, when I switch the network adapter to Bridged mode so that the VM gets its own IP address from the Fritzbox router, the problem occurs. The tunnel is established, but no data flows through it, and shortly after, the connection drops with an error message stating that the gateway is not responding.

• Device 2 (Notebook):
  The same issue occurs here, regardless if WIFI or Ethernet (direct connection to the Fritzbox). After the connection is established, the VPN client sends keep-alive packets, but no response is received. Shortly after, the connection also drops.

Error Messages from the Checkpoint Mobile Client Log:

• No reply from the gw ip=11.11.11.11 for tunnel test packet. Office Mode IP=22.22.22.22
• IKE tunnel disconnected, error code=-1000. Reason: Site is not responding.

Steps I’ve Already Tried:

1. Routing: Checked routes on both the VM and the notebook. No obvious issues. The default route correctly goes through the VPN.
2. Firewall: Checked the Fritzbox firewall. IPsec passthrough is enabled. No blocked ports or protocols were found.
3. MTU: Reduced the MTU value on both devices (down to 1300). No improvement.
4. Alternative Networks: Tested the connection via a mobile hotspot – the VPN tunnel works perfectly in this case.
5. DNS Settings: Tried different DNS servers (VPN-assigned and Google DNS). No improvement.

My Suspicion:

I suspect that the issue is either related to the Fritzbox configuration (routing or NAT) or the handling of the Office Mode IP by the Checkpoint Mobile Client.

Questions:

1. Are there any known issues with the Checkpoint Mobile Client in combination with Fritzbox routers (e.g., Bridged mode or NAT)?
2. What additional steps can I take to further diagnose or resolve the problem?

Thank you in advance for your support!

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Note: I’m not very good at English, so I used ChatGPT to help me write this text.

[thiagonavarro]

I have the same problem, generating the same error, same version of Windows 11. Help US!

[_Val_]

Please look into https://support.checkpoint.com/results/sk/sk182749 for resolution

[thiagonavarro]

Good Morning,

The solution presented is restricted.

[PhoneBoy]

The content of this SK is largely discussed here: https://community.checkpoint.com/t5/Remote-Access-VPN/Windows-11-24H2-Remote-Access-VPN/m-p/229233#M... 
Unless you can convince your admin to make the gateway-level changes, you'll most likely need to edit trac.defaults locally.

[sobife]

May someone that has the permission to read this document, post the solution here? i dont get why it is restricted. 

[PhoneBoy]

Unfortunately, some SKs require you to have a Support Agreement to access.
We cannot directly copy/paste SKs to the community. 
However, the thread I linked to has all the information in that SK.
Specifically, you change the following line in trac.defaults on the client:

route_conflict_resolution_method STRING "delete_create" GLOBAL 1

to

route_conflict_resolution_method STRING "modify" GLOBAL 1

Whether that will work in your case or not is a separate question.

[sobife]

Thank you for that. Unfortunately that is a solution for this problem that a colleague of mine found somewhere else. we already tried it and it didnt work in this case. is there a hint if this is a problem of windows or checkpoint?

[PhoneBoy]

There should be an option on the client to "Collect Logs."
Perhaps some clue will be present in those logs.
Otherwise, all I can suggest is engaging the TAC. 

[clausm]

I had the same problem, and the issue is the windows update 24H2, is very buggy. So I went back to the previous version 23H2 and it works again.