Product Documentation

Managing multiple network interface cards

Mar 08, 2017

Provisioning Services provides the ability to run redundant networks between the servers and the target devices. This requires that both the servers and the target devices be equipped with multiple network interface cards (NICs).

Multiple NICs on the target device may be configured into a virtual team by using Manufacturer’s NIC teaming drivers, or into a failover group using the Provisioning Services NIC failover feature.

NIC Teaming and NIC Failover features provide resilience to NIC failures that occur after the system is up and running. It is only after the OS has loaded that the actual NIC Team or NIC Failover group is established. If NIC failure occurs after being established:
  • The NIC Teaming feature allows the system to continue to function because the virtual MAC address is the same as the physical MAC address of the primary boot NIC.
  • The NIC Failover feature allows the system to continue to function because it automatically fails over to another NIC that was previously configured for this system.

When using a template with multiple NICs, Provisioning Services overwrites the network configuration of the first NIC. All the other NICs’ configurations are not changed. For a host with multiple network resources, Provisioning Services XenDesktop Setup wizard displays the network resources available to the host and allows you to select the network resource to associate with the first NIC.

Note: When a machine powers up, the BIOS goes through the list of available boot devices and the boot order of those devices. Boot devices can include multiple PXE-enabled NICs. Provisioning Services uses the first NIC in the list as the primary boot NIC. The primary boot NIC's MAC address is used as the lookup key for the target device record in the database. If the primary boot NIC is not available at boot time, Provisioning Services will not be able to locate the target device record in the database (a non-primary NIC may be able to just process the PXE boot phase). Although a workaround would be to add a separate target device entry for each NIC on each system, and then maintain synchronization for all entries, it is not recommended (unless the successful startup of a system is considered as critical as the continued operation of the system that is already running).

NIC teaming

When configuring NIC teaming, consider the following requirements:

  • Provisioning Services supports Broadcom and Intel NIC teaming drivers. A vDisk that is built after configuring NIC teaming can run Standard or Private Image Mode. Broadcom NIC Teaming Drivers v9.52 and 10.24b are not compatible with Provisioning Services target device drivers.
  • Teaming of multi-port network interfaces is not supported with Provisioning Services.
  • Multi-NIC is supported for XenDesktop Private virtual machine desktops. Using the wizard, Provisioning Services allows you to select the network to associate with the Provisioning Services NIC (NIC 0). The Delivery Controller provides the list of associated network resources for host connections.
  • The target device operating system must be a server-class operating system.
  • The new virtual team NIC MAC address has to match the physical NIC that performs the PXE boot.
  • Microsoft Windows Server 2012 built-in NIC teaming or OEM NIC teaming software should be installed and configured prior to the Target Device software.
  • Configure NIC teaming and verify that the selected teaming mode is expected by the application and the network topology. It should expose at least one virtual team NIC to the operating system.
  • When provisioning machines to a SCVMM server, the XenDesktop Setup wizard automatically changes the network configuration of both the first legacy NIC and the second synthetic NIC.
  • During the master target device installation process, Provisioning Services target device client drivers need to bind to the new virtual team NIC MAC address. If all physical NICs have been teamed up to a single virtual NIC, the Provisioning Services installer automatically chooses the virtual NIC silently, without prompting.
  • If changes are required, Provisioning Services Target Device software must be uninstalled before making changes to the teaming configuration, then reinstalled after changes are complete. Changes to teaming configurations on a master target device that has target device software installed, may result in unpredictable behavior.
  • When installing Provisioning Services target device software on NT6.x systems within a multi-NIC environment, all available NICs can be used. Therefore bindcfg.exe is no longer required and no longer installed with target device software.  

NIC failover

A Provisioning Services target device or Provisioning Server can be configured to support failover between multiple NICs. This feature works with any NIC brand or mixture of brands. Provisioning Services supports NIC failover for vDisks in either Standard and Private Image Mode.

  • The PXE boot NIC is considered the primary target device MAC address, which is stored in the Provisioning Services database.
  • You define the failover group of NICs when you run the Provisioning Services target device installer on the Master Target Device. If the machine has more than one NIC, the user is prompted to select the NICs in which to bind. Select all the NICs that participate in NIC failover.
  • A target device will only failover to NICs that are in the same subnet as the PXE boot NIC.
  • Teaming of multi-port network interfaces is not supported with Provisioning Services.
  • In the event that the physical layer fails, such as when a network cable is disconnected, the target device fails over to the next available NIC. The failover timing is essentially instantaneous.
  • The NIC failover feature and Provisioning Services HA feature compliment each other providing network layer failover support. If a failure occurs in the higher network layer, the target device fails over to the next Provisioning Server subject to HA rules.
  • The next available NIC from the failover group is used should the NIC fail and the target device reboots. NICs must be PXE capable and PXE enabled.
  • If a virtual NIC (teamed NICs) is inserted into the failover group, the vDisk becomes limited to Private Image Mode. This is a limitation imposed by NIC teaming drivers.
  • By default, Provisioning Services automatically switches from legacy Hyper-V NICs to synthetic NICs if both exist in the same subnet. To disable the default behavior (allowing for the use of legacy HyperV NICS even if synthetic NICs exist), edit the target device's registry settings: [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\BNIStack\Parameters] DisableHyperVLegacyNic"=dword:00000000
  • Load balancing is not supported in the NIC failover implementation.