Container networking on Kubernetes broken after Server 2022 July 2024 / KB5040437 (OS Build 20348.2582) update

[avin3sh]

Describe the bug Pod networking breaks after installing the July CU on Windows Server 2022. For eg, ping microsoft.com from within the container returns General failure. The pod is not reachable from the other pods or through a Service.

Uninstalling KB5040437 fixes the issue.

To Reproduce

• Setup a Windows worker with Calico VXLAN CNI provider (https://docs.tigera.io/calico/latest/getting-started/kubernetes/windows-calico/manual-install/standard)
• Install the July cummulative update on the Server 2022 worker
• Exec into a running container on the worker
• ping or curl any address

Expected behavior

The pod should be able to reach to external network as well should be reachable from other pods

Configuration:

• Edition: Windows Server
• Base Image being used: Windows Server Core
• Container engine: containerd
• Container Engine version: 1.6.31

/label Windows on Kubernetes