UD3900H ethernet connection to Win10 MS surface book keeps dropping connection and reconnecting


I have tried installing the new display link driver on your website.

The ethernet port connects and disconnects, and reconnects.

It fails immediately when I connect to a vnc session on vpn.



Thanks for reaching out to us, I am sorry this is not working as expected.

There are potentially multiple causes of the network disconnecting. I would like to get some additional details to help narrow down these causes.

When the network disconnects and reconnects, is this only happening when launching the VNC session after connecting to the VPN or when the VPN is attempting to connect? Additionally do connection errors occur while not connected to the VPN?

One possible cause of intermittent network connectivity is Windows attempting to connect to the WiFi network. As a quick test we can disable the WiFi ( airplane mode ) to see if this helps. To enable airplane mode in Windows 10, right-click on the WiFi icon in the system tray and select “Airplane Mode” from the popup menu.

Please let me know if enabling airplane mode helps,

Plugable Technology


With Wifi alone everything works.

Based on the below experiment, it seems to be isolated using ethernet with a VNC session.

In airplane mode (no WiFi)

Without VPN, VNC ~ 1 min no reconnection.

With VPN it works as well: ~ 1 min+

When I open a VNC session it starts to reconnect (connection reset by peer) - < RST packet on the network.



Thank you for the additional details and testing!

Just to confirm, when you launch the VNC viewer software and attempt to connect to the remote system, and the connection is reset by peer message comes up, is other network traffic also interrupted ( for example will web pages still load )?

Based on your description of the behavior, our next step is to get some additional information from your system.

If you would, please keep the dock connected and Ethernet cable connected to the docking station and attach the output of our diagnostic utility PlugDebug ( http://plugable.com/support/plugdebug ) to an email to support@plugable.com with the subject line “Ticket #269332 - Attention Pat” as this will allow us to examine some log files from your system to help determine the next steps.

Thank you,

Plugable Technology

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