Port 10250 (Kubelet API) — What It Is and How to Use It

Port 10250 is the default port for the Kubelet API, which is the primary agent that runs on each node in a Kubernetes cluster. It's crucial for the Kubernetes control plane to communicate with individual nodes, enabling pod management, container execution, and node health reporting.

Last updated: 2026-06-11

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                Port Number
                10250
            

Protocol Kubelet API

Common Use Cases

Receiving pod specifications from the API server and ensuring containers are running as expected.
Reporting node status, resource usage, and pod health back to the Kubernetes control plane.
Exposing metrics and logs for monitoring and debugging purposes.
Handling exec, attach, and port-forward requests for containers running on the node.

Interactive Command Builder

Target Host / IP

Operating System

Generated Command

nc -zv example.com 10250

Check if Port 10250 is Open

sudo netstat -tulnp | grep 10250

netstat -ano | findstr :10250

⚠️ Security Note: The Kubelet API on port 10250 is a highly privileged interface. Unauthorized access can lead to full control over the node and its running containers, making it a critical target for attackers. Proper authentication (e.g., client certificates, bearer tokens) and authorization (RBAC) are essential.

Related Ports

Frequently Asked Questions

Is port 10250 dangerous to leave open?

Yes, if left unsecured, port 10250 is extremely dangerous. It grants significant control over the node and its workloads. It should always be protected by strong authentication and authorization mechanisms, and ideally, only accessible from trusted components within the Kubernetes cluster.

What service uses port 10250?

Port 10250 is used by the Kubelet, which is the agent that runs on each worker node in a Kubernetes cluster. It's responsible for managing pods and their containers on that specific node.