Kubernetes ImagePullBackOff — cannot pull container image

Pod stuck in ImagePullBackOff or ErrImagePull status. The image exists in the registry but Kubernetes cannot pull it.

Common causes: (1) Image tag doesn't exist — check exact tag with docker pull locally. (2) Private registry needs imagePullSecrets configured on the pod or service account. (3) Image name typo — check registry/repo/tag format. (4) Rate limiting — Docker Hub limits pulls for anonymous users (100/6h). Use authenticated pulls or mirror. (5) Node can't reach registry — check network policies and DNS. Debug: kubectl describe pod shows exact pull error.

Kubernetes nodes pull images independently. Auth credentials, network access, and image availability must all work from the node's perspective, not your local machine.