---
title: The scheduler service should only be bound to localhost
description: Datadog, the leading service for cloud-scale monitoring.
breadcrumbs: >-
  Docs > Datadog Security > OOTB Rules > The scheduler service should only be
  bound to localhost
---

# The scheduler service should only be bound to localhost
Classification:complianceFramework:cis-kubernetesControl:1.4.2 
## Description{% #description %}

Do not bind the scheduler service to non-loopback insecure addresses.

## Rationale{% #rationale %}

The Scheduler API service which runs on port 10251/TCP by default is used for health and metrics information and is available without authentication or encryption. As such it should only be bound to a localhost interface, to minimize the cluster's attack surface

## Audit{% #audit %}

Run the following command on the master node:

```
ps -ef | grep kube-scheduler
```

Verify that the `--bind-address` argument is set to `127.0.0.1`.

## Remediation{% #remediation %}

Edit the Scheduler pod specification file `/etc/kubernetes/manifests/kube-scheduler.yaml` on the master node and ensure the correct value for the `--bind-address` parameter.

## Impact{% #impact %}

None

## Default value{% #default-value %}

By default, the `--bind-address` parameter is set to `0.0.0.0`.

## References{% #references %}

1. [https://kubernetes.io/docs/reference/command-line-tools-reference/kube-scheduler/](https://kubernetes.io/docs/reference/command-line-tools-reference/kube-scheduler/)

## CIS controls{% #cis-controls %}

Version 6.9.1 Limit Open Ports, Protocols, and Services - Ensure that only ports, protocols, and services with validated business needs are running on each system.

Version 7.9.2 Ensure Only Approved Ports, Protocols and Services Are Running - Ensure that only network ports, protocols, and services listening on a system with validated business needs, are running on each system.