How to configure DisplayLink Ethernet

Products based on the DL-6950, DL-5xxx and DL-3xxx can include gigabit Ethernet from DisplayLink. The Ethernet connection supports 10MB, 100MB or Gigabit Ethernet in full duplex. These speeds will be auto negotiated.

Half duplex connections, eg to network hubs, are not supported. A network link will not be established if connected to a half duplex port.

There are Ethernet features that can be configured. The screenshots below show the configuration on Windows 7, however the configuration is the same for all other Windows versions.

Note: it is unlikely you will need to configure any of these settings in a home environment. Contact your administrator to find out if you need to configure any of the settings in this section.

Advanced Ethernet features


Quick Links:

Opening the advanced Ethernet features


To access the advanced Ethernet features, Type ncpa.cpl into the Start menu search box:

Windows 7:


Windows 8.1:


Windows 10:



The "Network Connections" window opens. Locate the "DisplayLink USB Gigabit Network":


Right click on the icon and choose "Properties",then select "Configure…"

Choose the "Advanced" tab

Configuring the adapter MAC address




By default, every DisplayLink Ethernet port has its own unique layer 2 MAC address stored in the chip firmware. This MAC address will be used if the option Not Present is selected. The MAC address can be changed in the advanced properties.

To change the MAC address, Select the Value option and enter the new MAC address in the format XXXXXXXXXXXX, where X is a hex digit between 0 and F.

Click "OK" to apply the change

Additional MAC address configuration from 8.1 host software

See the section Configuring Ethernet settings remotely below for additional MAC address configuration options.

Configuring MAC address cloning or MAC address pass-through


You can configure the MAC address of the DisplayLink Ethernet port from various sources. These sources are listed in the priority order they will be applied below:
  1. Selected OEM laptop with dock MAC address passthrough on available configuration. You may reach out to technical support for details.
  2. MAC address set per Ethernet adapter interface under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E972-E325-11CE-BFC1-08002bE10318}\XXXX with a string value of NetworkAddress and a value in the format XXXXXXXXXXXX, where X is a hex digit between 0.
  3. MAC address set underHKEY_LOCAL_MACHINE\System\CurrentControlSet\services\dlcdcncm\Parameters\ with a string value of MacAddressOverride and a value in the format XXXXXXXXXXXX, where X is a hex digit between 0.
  4. Automatic wired/wireless MAC address cloning / pass-through
  5. Default MAC address of the dock hardware is used
Option 2 is should be the chosen option for an IT manager to implement MAC address passthrough. This can be used in conjunction with a script to obtain a MAC address from a location on the PC, and ensure that MAC address is always used for a DisplayLink Ethernet connection. An example Windows Powershell script, which gets the MAC address of first Ethernet interface found on the PC and sets it in the registry can be downloaded here. Note that the script needs to be run with administrator privileges, so it can write to the Windows registry.

IT managers need to be careful when choosing and configuring their MAC address passthrough policy that more than one interface with the same MAC address cannot be connected to the same network at the same time. Having duplicate MAC addresses on a network will cause network issues. 

Automatic wired/wireless MAC address cloning or MAC address pass-through

From DisplayLink USB Graphics Software for Windows with Hot Desking version 10.1 (available from our corporate download section), you can enable automatic configuration of MAC address pass-through. It does not replace existing possibility of configuring MAC address pass-through, but rather extends it. 
Feature is controlled by registry key under HKEY_LOCAL_MACHINE\Software\Displaylink\Core with string value MACAddressPassthrough and a value of ‘1’.
When feature is enabled and dock is plugged-in, registry key HKEY_LOCAL_MACHINE\System\CurrentControlSet\services\dlcdcncm\Parameters\MacAddressOverride is filled in with MAC address cloned from existing ethernet adapter. It is strongly advised to have one network cable connected to the system to avoid situation where two adapters with the same MAC address are connected to the network.
Existing MAC address pass-through registry key value is backed-up to registry key HKEY_LOCAL_MACHINE\System\CurrentControlSet\services\dlcdcncm\Parameters\MacAddressOverrideBackup which is restored, when dock is unplugged.
To choose the best MAC address, following rules are applied:
  • MAC address is cloned from wired adapter first.
  • If case on no wired adapter, wireless (802.11) device is chosen when available.
  • Link status (is adapter connected and active) is not checked. This is planned for a future version.
  • Any DisplayLink docks, virtual adapters like VPN, VMWare, VirtualBox or Bluetooth adapters are ignored.
  • OEM laptop + dock MAC address passthrough functionality takes priority and disables the automatic configuration of MAC address cloning of wired/wireless network adapters.
IMPORTANT: as link status is not checked, the user MUST NOT connect both the laptop wired and DisplayLink Ethernet devices at the same time when using this functionality. It would otherwise present the same MAC address on two different network ports and cause problems.

Configuring the Link Speed




The link speed can be set Auto negotiate (default), 10Mbps full duplex, 100Mbps full duplex or 1Gbps full duplex. Half duplex speeds are not supported. 

Configuring the adapter VLAN ID




The VLAN tag can be set. By default the VLAN tag is set to 0, which will transmit all packets priority tagged. The VLAN tag can be between 1 and 4095.

On Windows 7 and Windows 8 VLAN Tagging will also need to be enabled under the "Priority and Vlan" menu:



Click "OK" to apply the change

Configuring Wake on LAN


Wake on LAN is enabled and disabled under the Power Management tab:



To enable Wake on LAN, which will wake the computer on Link Up and Magic packet, check the box to Allow this device to wake the computer.

Note: This option will be greyed out if not supported by your PCs USB Host controller or BIOS.

Wake on Magic Packet also needs to be enabled under the "Advanced" tab:



The DisplayLink device will need to be disconnected and reconnected to the USB bus before the settings take effect.

Wake on LAN will wake the PC from an S3 (suspend or sleep) state. It may fail if the PC turns off the USB connection during S3 on battery power.  It will not wake the PC from an S4 (Hibernate) or S5 (Off) state.

Configuring Wake on Magic Packet only

To allow Wake on Magic packet only, also check the option to "Only allow a magic packet to wake the computer". Also Enable Wake on Magic Packet under the Advanced Tab:


After applying the changes, the DisplayLink device will need to be disconnected and reconnected to the USB bus before the settings take effect.

Wake on LAN will wake the PC from an S3 (suspend or sleep) state. It may fail if the PC turns off the USB connection during S3 on battery power.  It will not wake the PC from an S4 (Hibernate) or S5 (Off) state.

Configuring Ethernet settings remotely


This section is designed for IT administrators only to allow them to remotely set Ethernet parameters. This section should only be followed if you are an advanced user, familiar with the Windows registry.

It is possible to set the Ethernet options remotely through the Windows registry on the PC. The settings are stored under:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E972-E325-11CE-BFC1-08002bE10318}

There is a list of numeric keys under here, starting at 0000. Each of the keys are the settings for a network card. This can be found under the details tab, under the Driver Key properties. In the example below, it is 0022:



The parameters are held below this registry key.

Network Address

The network address can be set by adding a new String Value, with the Name NetworkAddress. The value should be in the format XXXXXXXXXXXX, where X is a hex digit between 0 and F.

VLAN ID

The VLAN ID can be set by adding a new String Value, with the Name VlanID. The value should be between 0 and 4095. Setting 0 will disable tagging.

Wake on LAN

Wake on LAN is enabled by setting the PnPCapabilities to “0”. To disable Wake on LAN, set PnPCapabilities to “110” (Hex).

To set the Wake on LAN method, add a String Value with the Name WakeOnLan and a value. A list of the possible values are stored below here in the registry under Ndi/params/WakeOnLan/enum. Use the Name (0 to 3) of these enums as the Value for WakeOnLan

Jumbo frames


Jumbo frames are not supported on DL-3xxx, DL-5xxx or DL-6xxx series Ethernet ports. Disable jumbo frames on any network with DisplayLink Ethernet ports connected, otherwise problems could be found with network behaviour.

Uninstalling just the Ethernet driver


In a corporate environment, it might be desired that the Ethernet driver is not installed to prevent the Ethernet port of the dock being available and a security risk. The Ethernet driver can be uninstalled after deploying DisplayLink software by:
  • Running pnputil to find the inf file for the driver in the Windows driver store. Eg: pnputil -a C:\Program Files\DisplayLink Core Software\CdcNcmDriver\dlcdcncm.inf
  • Process pnputil output to get "oemXX.inf" file name
  • Remove the Ethernet driver with the command pnputil -f -d oemXX.inf

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