Windows Server 2025 Datacenter - LBFO is failing/deprecated - no full link speed with New-VMSwitch command

Question

Name: Microsoft Windows Server 2025 Datacenter
OS Version: 10.0.26100 N/A Build 26100

LBFO is deprecated with Windows Server 2025. Instead of using a traditional NIC teaming, I created the Hyper-V vSwitch with the following command:

New-VMSwitch -Name "vSwitch" -NetAdapterName "SLOT 6 Port 1","SLOT 6 Port 2","SLOT 6 Port 3","SLOT 6 Port 4" -EnableEmbeddedTeaming $true -AllowManagementOS $true

So far, everything is fine; by default, the Load Balancing mode is set to HyperVPort. However, even though I have 4x 1 Gbps connections, it shows only a LinkSpeed of 1 Gbps. When I choose Dynamic as the LoadBalancingAlgorithm, it shows a LinkSpeed of 4 Gbps:

PS C:\Users\Administrator> Set-VMSwitchTeam -Name "vSwitch" -LoadBalancingAlgorithm Dynamic
PS C:\Users\Administrator> Get-NetAdapter | Sort-Object Name

Name                      InterfaceDescription                    ifIndex Status       MacAddress             LinkSpeed
----                      --------------------                    ------- ------       ----------             ---------
Embedded NIC 1            Broadcom NetXtreme Gigabit Ethernet #2        6 Disconnected C4-CB-E1-E3-82-A8          0 bps
Embedded NIC 2            Broadcom NetXtreme Gigabit Ethernet #5       11 Disconnected C4-CB-E1-E3-82-A9          0 bps
SLOT 6 Port 1             Broadcom NetXtreme Gigabit Ethernet           2 Up           8C-84-74-0A-38-E8         1 Gbps
SLOT 6 Port 2             Broadcom NetXtreme Gigabit Ethernet #4        9 Up           8C-84-74-0A-38-E9         1 Gbps
SLOT 6 Port 3             Broadcom NetXtreme Gigabit Ethernet #6       13 Up           8C-84-74-0A-38-EA         1 Gbps
SLOT 6 Port 4             Broadcom NetXtreme Gigabit Ethernet #3       14 Up           8C-84-74-0A-38-EB         1 Gbps
vEthernet (vSwitch)       Hyper-V Virtual Ethernet Adapter              8 Up           8C-84-74-0A-38-E8         4 Gbps

When I change the LoadBalancingAlgorithm back to HyperVPort, it shows only a LinkSpeed of 1 Gbps again:

mathematicaKopierenPS C:\Users\Administrator> Set-VMSwitchTeam -Name "vSwitch" -LoadBalancingAlgorithm HyperVPort
PS C:\Users\Administrator> Get-NetAdapter | Sort-Object Name

Name                      InterfaceDescription                    ifIndex Status       MacAddress             LinkSpeed
----                      --------------------                    ------- ------       ----------             ---------
Embedded NIC 1            Broadcom NetXtreme Gigabit Ethernet #2        6 Disconnected C4-CB-E1-E3-82-A8          0 bps
Embedded NIC 2            Broadcom NetXtreme Gigabit Ethernet #5       11 Disconnected C4-CB-E1-E3-82-A9          0 bps
SLOT 6 Port 1             Broadcom NetXtreme Gigabit Ethernet           2 Up           8C-84-74-0A-38-E8         1 Gbps
SLOT 6 Port 2             Broadcom NetXtreme Gigabit Ethernet #4        9 Up           8C-84-74-0A-38-E9         1 Gbps
SLOT 6 Port 3             Broadcom NetXtreme Gigabit Ethernet #6       13 Up           8C-84-74-0A-38-EA         1 Gbps
SLOT 6 Port 4             Broadcom NetXtreme Gigabit Ethernet #3       14 Up           8C-84-74-0A-38-EB         1 Gbps
vEthernet (vSwitch)       Hyper-V Virtual Ethernet Adapter              8 Up           8C-84-74-0A-38-E8         1 Gbps

Is there a way in Windows Server 2025 to use the HyperVPort LoadBalancingAlgorithm in combination with the full bandwidth of the NIC team? If not can for example 4 virtual machines each use 1 Gbps simultaneously or do all 4 virtual machines share a total of 1 Gbps if the LoadBalancingAlgorithm is HyperVPort?

Answer 1

Thanks for the tip. I've now posted it in the correct forum.

Windows Server 2025 Datacenter - LBFO is failing/deprecated - no full link speed with New-VMSwitch command

Answer 2

Dear FAMO1403,

Thank you for reaching out and sharing the detailed description of the issue you're facing with LBFO and the Hyper-V virtual switch configuration on Windows Server 2025 Datacenter.

This is a specialized and complex issue related to the changes in networking features in Windows Server 2025, particularly regarding the deprecation of LBFO and the use of the new Hyper-V virtual switch configurations. Unfortunately, the issue falls beyond the scope of support provided by the basic Windows boards. The networking configuration and performance considerations you're dealing with are more advanced and specific to Windows Server environments.

For this type of specialized issue, I highly recommend posting your question to the Windows Server Boards. The community there, including experts in server management and networking, will be able to offer more tailored guidance and troubleshooting steps specific to Windows Server 2025.

Ask a question - Microsoft Q&A

I hope your issue is successfully resolved after reaching out to the right community.

Best Regards,

Martin | Microsoft Community Support Specialist