microsoft / microsoft/Windows-Containers

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

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🔖 ADO bug Networking Windows on Kubernetes
Dominant language
PowerShell
Stars
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Forks
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PR merge metrics
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Description

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

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

Contributor guide

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First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Reproduce on a Windows Server 2022 worker using the documented Calico VXLAN setup, containerd 1.6.31, and the July cumulative update KB5040437. Start by comparing pod networking before and after the update, including ping or curl from a container and pod-to-pod or Service access. Done means pod external, pod-to-pod, and Service connectivity work without uninstalling the update.

Written by the indexing model from the issue text.

Assessment

Tech stack
kubernetes
Domain
infrastructure, networking, operating-systems
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Active
Clarity
Mostly clear
Newbie friendliness
42/100

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