NAVClient hang at splash screen for 20 minutes, then shows connection lost

gnrfan
gnrfan Member Posts: 4
edited 2024-01-19 in NAV Three Tier
Hello community, hope you can help me.

We opened a new location for our company. The new location should use our NAV 2013 CU58 via NAVUserPassword authentication. At first we gave them a OpenVPN Client and the NavClient runs fine at the new location.
Now we established an IPsec Tunnel between our location and the new one. 
Looking like this
Home net
Firewall
Internet
Router at new location
VPNGateway and Clients at the new location net

For Testing, alls ports are open in both directions and routing through the VPNGateway ist set on the Clients at the new location.
Ping runs good in all directions  Middle Tier and all Servers <----> new Clients

If we start the NAV Client, it shows the splash screen, makes the entry to the Active Session Table, but the Start Screen of NAV does not appear.
After round about 20 minutes the Nav client shows the error of a lost connection to the server.

What i've tried:
Disable all Addins for the Startpage and use a simple profile
Make entries at the Clients hosts-File for NAV-Server, DB-Server, DCs, Exchange, CA, Third-party-Archive in case of DNS issues
optimizing MTU for the tunnel
capture the net traffic to search for unresponded dns request or other 
Rename the addin directory of the NAV Client to disable third party dlls
Checking Event Log at Server and Client

has anybody an idea what i can check addinially or did anyone know the start procedure of the client, so i can check step by step which part is failing?

Best Answer

  • gnrfan
    gnrfan Member Posts: 4
    Answer ✓
    Today it was possible to do some more tests.
    With a lower MTU than tested before on the network card of the client the connection was possible and fast.
    Now i've to optimize the settings of the tunnel but the topic here has its solution.

    Thank you Aluan!

Answers

  • gnrfan
    gnrfan Member Posts: 4
    Not a single idea?
  • Aluan
    Aluan Member Posts: 164
    Hey gnrfan,
    you tried a few things, are there any events logged in the eventlog which you can share, or are there no events at all?

    Looks like the initial connection works, but you don't get a response. I would check the Firewall Logs (deep packet inspection?).
  • gnrfan
    gnrfan Member Posts: 4
    there are no events at all. after the 20 minutes the lost connection is shown in the clients eventlog. i've tried to start the client with disabled local firewall and antivirus.
    As the connection is encrypted, i don't know the steps client and server would do, till the client screen is shown.
  • Aluan
    Aluan Member Posts: 164
    Just to make sure, are you seeing a logon event on the Server? Should be Event id 4624.

    You state above that the connection with OpenVPN did work, but not with the IPsec Tunnel, do you have access to the logs? I still think the Server is receiving the request for the connection, that is why you can see the session, but the client doesn't get any response. That's probably because of the firewall. But the logs should help here.

    Not sure about the exact steps, it's probably like the client is requesting access -> server responds -> client logins (if allowed). The seconds step is probably the problem here.
  • gnrfan
    gnrfan Member Posts: 4
    Answer ✓
    Today it was possible to do some more tests.
    With a lower MTU than tested before on the network card of the client the connection was possible and fast.
    Now i've to optimize the settings of the tunnel but the topic here has its solution.

    Thank you Aluan!
  • Aluan
    Aluan Member Posts: 164
    Interesting, glad you could solve it! Thank you for the update.

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