Port 6443: Kubernetes API
Port 6443 is the default port for the Kubernetes API server, the control-plane endpoint that kubectl and every cluster component talk to. Access to it is effectively access to the whole cluster, so it is normally protected with strong authentication and network policy.
| Port number | 6443 |
|---|---|
| Service | Kubernetes API server |
| Protocol | TCP |
| Category | Infrastructure & orchestration |
| Default encryption | No |
Frequently asked questions
What is port 6443 used for?
Port 6443 is the default port for the Kubernetes API server, the control-plane endpoint that kubectl and every cluster component talk to. Access to it is effectively access to the whole cluster, so it is normally protected with strong authentication and network policy.
Is port 6443 TCP or UDP?
Port 6443 (Kubernetes API) uses TCP.
Is port 6443 secure?
Port 6443 is not encrypted by default. Where possible, use an encrypted alternative or tunnel it over TLS or a VPN.
Should I open port 6443 on my firewall?
Only if you specifically need Kubernetes API. Expose it to the smallest set of trusted sources, and never open database or Windows-service ports to the whole internet.