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Example: Configuring a PTP Boundary Clock With Unicast Negotiation

This example shows how to configure a boundary clock with unicast negotiation turned on and a mixture of manual, secure and automatic clock clients, which have a client relationship to the primary boundary clock. The unicast negotiation applies to clock sources, which are configured on the client or clock client. Clock clients, configured on the primary, are not affected by unicast negotiation.

Note:

ACX5048 and ACX5096 routers do not support boundary clock.

In this example, unicast-negotiation is applicable only to clock-sources. For clock clients, the statement unicast-negotiation at the [edit protocols ptp] hierarchy level is not effective.

Requirements

This example uses the following hardware and software components:

Note:

This example also applies to QFX Series switches. QFX Series switches do not support Gigabit Ethernet interfaces. Instead, configure PTP boundary clock parameters on 10-Gigabit Ethernet interfaces.

  • An ACX Series router

  • Junos OS Release 12.3 or later

Overview

A PTP client clock or clock client can join a primary clock with and without unicast negotiation. With unicast negotiation, the announce, synchronization, and delay response packet rates are negotiated between the primary and the client before a PTP session is established. Without unicast negotiation and after it is configured, the client or client immediately receives announce and synchronization packets.

A clock client is the remote PTP host, which receives time from the PTP primary. The following clock clients are configured in this example:

  • Secure client—A secure client is configured with an exact IP address, after which, it joins a primary clock through unicast negotiation. In this example, the clock client clock-client 117.117.117.117/32 local-ip-address 109.109.109.53 is a secure client, which means that only this specific host from the subnet can join the primary clock through a unicast negotiation .

  • Automatic client—An automatic client is configured with an IP address, which includes a subnet mask, indicating that any PTP host belonging to that subnet, can join the primary clock through a unicast negotiation. In this example, the clock client clock-client 109.109.109.0/24 local-ip-address 109.109.109.53 is an automatic client. Additionally, this automatic client is configured on the same primary clock interface—109.109.109.53—as the secure client.

  • Manual client—A manual client does not use unicast negotiation to join the primary clock. The manual statement overrides the unicast-negotiation statement configured at the [edit protocols ptp] hierarchy level. As soon as you configure a manual client, it starts receiving announce and synchronization packets. In this example, the clock client clock-client 7.7.7.7 local-ip-address 7.7.7.53 manual is the manual client and is configured on a second primary clock interface.

Configuration

A boundary clock must include the configuration of at least one primary and at least one client. The boundary primary receives time from a remote primary through the client, and in turn passes that time on to clock clients, which are in a client relationship to the boundary primary. In this example, you configure a boundary client, two Precision Time Protocol (PTP) boundary primaries with three different kinds of clock clients—automatic, manual, and secure. Two of the clock clients are configured on the same boundary primary.

Procedure

CLI Quick Configuration

To quickly configure this example, copy the following commands, paste them in a text file, remove any line breaks, change any details necessary to match your network configuration, and then copy and paste the commands into the CLI at the [edit] hierarchy level:

Step-by-Step Procedure

The following example requires you to navigate various levels in the configuration hierarchy. For information about navigating the CLI, see Using the CLI Editor in Configuration Mode in the CLI User Guide.

To configure a boundary clock with unicast negotiation:

  1. Configure the clock mode.

  2. Enable unicast negotiation.

  3. Configure the local client interface from which the boundary primary receives time and passes it on to the configured clock clients.

  4. Configure the upstream unicast PTP primary clock source parameters.

  5. Configure the encapsulation type for PTP packet transport.

  6. Configure the PTP primary parameters by specifying the IP address of the PTP primary clock and the IP address of the local interface.

  7. Configure the first primary interface in this example.

  8. On the first primary interface, configure the downstream PTP clock clients.

  9. On the first primary interface, configure the encapsulation type for PTP packet transport.

  10. On the first primary interface, configure the PTP primary parameters by specifying the exact IP address of the remote PTP host and the IP address of the local PTP primary interface.

  11. On the first primary interface, configure a second PTP primary by specifying the IP address and subnet of the second remote PTP host and the IP address of the local PTP primary interface.

  12. Configure the second primary interface with the following parameters: the encapsulation type, the downstream PTP host, the IP address of the local PTP primary interface, and the manual statement so that this client does not use unicast negotiation.

Results

From configuration mode, confirm your configuration by entering the show command. If the output does not display the intended configuration, repeat the configuration instructions in this example to correct it.

After you have configured the device, enter the commit command from configuration mode.

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