---
title: "Testing PTP Clock on an Ubuntu Docker Host"
slug: "testing-ptp-clock-on-an-ubuntu-docker-host"
updated: 2025-02-21T21:58:04Z
published: 2025-02-21T21:58:04Z
canonical: "docs.telosalliance.com/testing-ptp-clock-on-an-ubuntu-docker-host"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.telosalliance.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Testing PTP Clock on an Ubuntu Docker Host

## Scope

This document covers the steps required to confirm proper PTP clock operation on an Ubuntu host system where Docker containers are hosted.

## Description

When installing many containerized Telos Alliance products (VXs in this example) the product uses the host clock. This is contrary to some Livewire+ products that sync to PTP (or Livewire) clock directly. In this example, the host clock is synchronized to a PTP master clock and the container gets its clock from the host operating system.

## Checking PTP Clock

The easiest way to test PTP clock on the host is to install **linuxptp** in Ubuntu if not already installed.

### Installing the linuxptp program

1. Using a terminal program connect to your Ubuntu host.

> [!NOTE]
> If you installed Ubuntu with a Desktop environment you can use the terminal program there. You can also use PuTTy or another terminal program to make an SSH connection remotely. In our example, we are using Terminal and connecting over the network using SSH.
2. Install the Linux program linuxptp using ***apt-get install.*** From the prompt;

```plaintext
dbjones@vxs:~$ sudo apt-get install linuxptp
```
3. From the command line, run the following command where eth1 is YOUR interface connected to the network with PTP.

```plaintext
dbjones@vxs:~$ sudo ptp4l -s -m -H -i eth1
```

> [!WARNING]
> Use -S in place of -H if hardware time stamp is not available