Windows NIC Teaming using PowerShell (Part 8)

by [Published on 6 Feb. 2014 / Last Updated on 6 Feb. 2014]

The concluding article in this series examines some additional considerations when implementing Windows NIC Teaming in both physical and virtual environments using Windows PowerShell.

If you would like to read the other parts in this article series please go to:

Summary of considerations so far

Here is a quick summary of what we've learned so far in terms of the considerations involved when implementing Windows NIC Teaming in physical and virtual environments.

Considerations for physical environments

The following functionalities included in some physical network adapters are not supported when these adapters are teamed together on a physical server using Windows NIC Teaming:

  • 802.1X authentication
  • Remote Direct Memory Access (RDMA
  • Single-Root I/O Virtualization (SR-IOV)
  • TCP Chimney Offload
  • Quality of Service (QoS)

Other considerations when implementing Windows NIC Teaming with physical network adapters in physical servers include the following:

  • A team can have a minimum of one physical network adapter and a maximum of 32 physical network adapters.
  • All network adapters in the team should operate at the same speed i.e. 1 Gpbs. Teaming of physical network adapters of different speeds is not supported.
  • Any switch ports on Ethernet switches that are connected to the teamed physical network adapters should be configured to be in trunk mode i.e. promiscuous mode.
  • If you need to configure VLANs for teamed physical network adapters, do it in the NIC teaming interface (if the server is not a Hyper-V host) or in the Hyper-V Virtual Switch settings (if the server is a Hyper-V host).

Considerations for virtual environments

The following considerations should be kept in mind when implementing Windows NIC Teaming with virtual network adapters within virtual machines running on Hyper-V hosts:

  • Each virtual network adapter must be connected to a different virtual switch on the Hyper-V host on which the virtual machine is running. These virtual switches must all be of the external type--you cannot team together virtual network adapters that are connected to virtual switches of either the internal or private type.
  • The only supported teaming mode when teaming virtual network adapters together is the Switch Independent teaming mode.
  • The only supported load balancing mode when teaming virtual network adapters together is the Address Hash load balancing mode.
  • If you need to configure VLANs for teamed virtual network adapters, make sure that the virtual network adapters are either each connected to different Hyper-V virtual switches or are each configured using the same VLAN ID.

In addition, we have also learned that Address Hash load balancing can be configured using PowerShell to utilize one of three different kinds of hashing methods:

  • TCP Ports  Uses the source and destination TCP ports and also the source and destination IP addresses as inputs for the hashing function. Note that this is the default hashing method when Address Hash is selected in the NIC Teaming GUI as the load balancing mode for the team.
  • IP Addresses  Uses only the source and destination IP addresses as inputs for the hashing function.
  • MAC Addresses  Uses only the source and destination MAC addresses as inputs for the hashing function.

Additional considerations

To conclude this series of articles, here are some additional considerations you need to be aware of when planning on implementing Windows NIC Teaming in physical and virtual environments.

Additional considerations for physical environments:

  • Only Ethernet adapters can be used for NIC teams on physical servers. You cannot use Infiniband adapters, WLAN adapters, Bluetooth adapters and so on in NIC teams.
  • You cannot team Hyper-V switch ports (vNICs) exposed as network adapters on Hyper-V hosts.
  • You cannot team a physical network adapter used for PXE-booting the server.
  • Teaming of physical network adapters that operate at different speeds is not supported. However, standby team members that operate at a slower speed than active team members are supported.
  • Windows NIC Teaming should not be implemented together with a third-party NIC teaming solution on the same physical server even if different physical network adapters are used for each team.

Additional considerations for virtual environments:

  • Using more than two virtual network adapters in a team is not supported.
  • Changing the MAC address of a team within a virtual machine is not supported.
  • You should remove all teams from a server running Windows Server 2012 before performing an in-place upgrade to Windows Server 2012 R2. Then re-create the teams after the upgrade.

Additional considerations for both physical and virtual environments:

  • All team members must be connected to the same subnet in your network environment.
  • Network intrusion detection systems (NIDS) and firewalls may have difficulty resolving traffic through a NIC team because packets from the same IP address may have different MAC addresses. Adjust your NIDS and firewall filters accordingly.

Last resort troubleshooting

If you neglect any of the above considerations, your NIC team might get into an unstable state resulting in loss of network connectivity with your server. If this happens, you should follow this procedure to remove all NIC teams from your server:

  1. 1. Reboot the server, log on again and run the following command:
    PS C:\> Get-NetLbfoTeam | Remove-NetLbfoTeam
  2. 2. Reboot the server again and all NIC teaming configuration should be removed.

A similar procedure can be used if the problem involves a virtual machine instead of a physical server.

If you would like to read the other parts in this article series please go to:

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