Monthly security updates (KB 5021249 and KB 5021237) for Hyper-V hosts released on Dec 13th, 2022, have known issues that impacts SCVMM managed SDN (Software Defined Networking) deployments and this creates failures with new VM creation and virtual network assignment.
If your infrastructure meets all the following criteria, then it is impacted; Please apply the fix shared below after patching.
SCVMM managed Hyper-V hosts (Azure Stack HCI clusters, Windows Server 2019, Windows Server 2022) patched with KB 5021249 and KB 5021237 update.
SCVMM version 2019 or SCVMM version 2022 configured with Network Controller.
Hyper-V patched with KB 5021249 or KB 5021237
2012 R2, 2016, 2019, HCI 21H2
2012 R2, 2016
2019, HCI 21H2
2016, 2019, 2022, HCI 22H2
2019, 2022, HCI 22H2
If you don’t apply the solution after patching the Hyper-V hosts with KB 5021249 and KB 5021237, the following could occur:
New VM creation fails: Creating a new VM with Network adapter fails.
SLB Load Balancer or SDN RAS Gateway fails with an ‘EthernetConnection’ error
Attaching vNIC fails: Attaching a Network adapter to an existing VM .
Warning message during live migration: Live migration of Non-Highly Available VMs completes with ‘EthernetConnection’ warning message.
An error message like the one below is seen in these scenarios:
If you encountered the above issues, after patching SCVMM managed Hyper -V hosts with KB 5021249 and KB 5021237, we recommend installing the appropriate Cumulative update from below on all SCVMM managed Hosts.
If you haven’t patched SCVMM managed Hyper-V hosts with ‘KB 5021249 and KB 5021237’ updates, we recommend skipping the updates ‘KB 5021249 and KB 5021237’ and manually install the following Cumulative updates on all SCVMM managed Hosts.
Windows Server 2022: KB5022553 – Link to download the KB from Microsoft Update Catalog
Windows Server 2019: KB5022554 – Link to download the KB from Microsoft Update Catalog
The above updates are not available from Windows Update and will not be installed automatically.