Answers: <p>According to <a href="https://github.com/rancher/rke/issues/212" rel="nofollow noreferrer">this page</a> it is used for <code>kubeproxy</code>.</p>
  <blockquote>
  <p>The Kubernetes network proxy runs on each node. This reflects services as defined in the Kubernetes API on each node and can do simple TCP, UDP, and SCTP stream forwarding or round robin TCP, UDP, and SCTP forwarding across a set of backends. Service cluster IPs and ports are currently found through Docker-links-compatible environment variables specifying ports opened by the service proxy. There is an optional addon that provides cluster DNS for these cluster IPs. The user must create a service with the apiserver API to configure the proxy.</p>
  <p>[...]</p>
  <p><code>--healthz-bind-address ipport     Default: 0.0.0.0:10256</code></p>
  <p>The IP address with port for the health check server to serve on (set to '0.0.0.0:10256' for all IPv4 interfaces and '[::]:10256' for all IPv6 interfaces). Set empty to disable. This parameter is ignored if a config file is specified by --config.</p>
  </blockquote>
  <p><strong>References</strong><br />
  <a href="https://kubernetes.io/docs/reference/command-line-tools-reference/kube-proxy/" rel="nofollow noreferrer">kube-proxy</a></p>
  
Answers: CC BY-SA 4.0
Answers: 2022-07-07T18:59:23.037Z
Answers: 2023-04-04T10:19:08.397Z
Answers: 2023-04-04T10:19:08.397Z
Answers: kenlukas
Body: <p>What does TCP 10256 do and where is to documented. According to the <a href="https://rancher.com/docs/rancher/v2.5/en/installation/requirements/ports/#rancher-aws-ec2-security-group" rel="nofollow noreferrer"><em>&quot;Rancher AWS EC2 Security Grouplink&quot;</em></a> it's open. But I don't see any documentation on port 10256 elsewhere.</p>
  <p>It's also documented on the similar <a href="https://rancher.com/docs/rancher/v2.6/en/cluster-provisioning/rke-clusters/node-pools/azure/azure-machine-config/" rel="nofollow noreferrer"><em>&quot;Azure machine config&quot;</em></a></p>
  
Tags: <amazon-web-services><rancher><ports>
Title: Why does the Rancher Security Group use TCP Port 10256?
UserDisplayName: Evan Carroll
ThreadText: # Why does the Rancher Security Group use TCP Port 10256?
  
  (Asked by: username_0 on 2022-07-05)
  
  What does TCP 10256 do and where is to documented. According to the [*"Rancher AWS EC2 Security Grouplink"*](https://rancher.com/docs/rancher/v2.5/en/installation/requirements/ports/#rancher-aws-ec2-security-group) it's open. But I don't see any documentation on port 10256 elsewhere.
  
  It's also documented on the similar [*"Azure machine config"*](https://rancher.com/docs/rancher/v2.6/en/cluster-provisioning/rke-clusters/node-pools/azure/azure-machine-config/)
  
  **Tags:** amazon-web-services, rancher, ports
  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2022-07-07. Score: 1
  
  According to [this page](https://github.com/rancher/rke/issues/212) it is used for `kubeproxy`.
  
  > The Kubernetes network proxy runs on each node. This reflects services as defined in the Kubernetes API on each node and can do simple TCP, UDP, and SCTP stream forwarding or round robin TCP, UDP, and SCTP forwarding across a set of backends. Service cluster IPs and ports are currently found through Docker-links-compatible environment variables specifying ports opened by the service proxy. There is an optional addon that provides cluster DNS for these cluster IPs. The user must create a service with the apiserver API to configure the proxy.
  >
  > [...]
  >
  > `--healthz-bind-address ipport Default: 0.0.0.0:10256`
  >
  > The IP address with port for the health check server to serve on (set to '0.0.0.0:10256' for all IPv4 interfaces and '[::]:10256' for all IPv6 interfaces). Set empty to disable. This parameter is ignored if a config file is specified by --config.
  
  **References**  
  [kube-proxy](https://kubernetes.io/docs/reference/command-line-tools-reference/kube-proxy/)
  
  
  ---
  
  