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