Example: Configuring PTP over Ethernet for Multicast Primary, Member, and Dynamic Ports
In PTP over Ethernet networks, the primary sends the announce, synchronization, and delay-response packets using the multicast method. If any unicast delay-request message is received, the primary disregards the message and does not send delay-response messages to the client. A PTP client receives the multicast announce packets from the primary or multiple primaries and determines the best primary using Best Master Clock Algorithm (BMCA). A client receives and processes the synchronization from the selected primary clock. The client sends delay-request messages to this primary using the multicast method and processes the delay-response messages from the primary to establish synchronization.
Both the link-local MAC address and the standard 802.3 multicast MAC address can be present in a system. However, a PTP interface supports only one of the following at a point in time:
Layer 2 multicast with link-local MAC address
Layer 2 multicast with standard multicast MAC address
PTP over IPv4
When you configure both IPv4 and Ethernet encapsulation, the unicast-negotiation configuration applies only to IPv4 encapsulation. It is not effective for PTP over Ethernet operation.
When you configure a logical interface by using the stateful statement at the [edit protocols ptp] hierarchy level,
each interface that you configure as a stateful or dynamic port is
considered to be both a master and a client port. Although an ACX
Series router supports up to 32 master ports and 4 client ports, you
can configure only 4 unique logical interfaces as potential PTP masters
by using the stateful statement because the interface is
treated as both a client and a master interface. You cannot configure
the interface that you specify to be a stateful or dynamic port with
the master or slave statements.
This example shows how to configure a master port, client port, and a dynamic port for PTP over Ethernet and PTP over IPv4 encapsulation, and how to configure unicast and multicast mode of transmission of PTP traffic among the master and client nodes.
Requirements
This example uses the following hardware and software components:
An ACX Series router
Junos OS Release 12.3X51 or later
Overview
While an ACX Series router supports the PTP over Ethernet functionality, a Brilliant Reference Clock such as an MX Series router or a TCA Series Timing Client does not support PTP over Ethernet. Consider a sample deployment in which an ACX Series router named ACX1 functions as a boundary clock with a PTP client port using IPv4 as the encapsulation mode and master ports using Ethernet as the encapsulation mode for PTP traffic. ACX1 contains two potential client interfaces, one that is fixed as a client-only port using IPv4 on the link toward an MX Series router named MX2, and a dynamic port that functions as a client using PTP over Ethernet on the link toward another ACX Series router named ACX2. In addition, ACX1 also contains a port that is a master-only port using PTP over Ethernet and connects to the base station.
In this example, the router uses either interface ge-0/2/0.0 or ge-0/2/1.0 as the selected client interface based on the announce messages received from the master and the port that was selected using the Best Master Clock Algorithm (BMCA). The interface ge-0/1/4.0 is always in the master state. According to the IEEE 1588 specification, if port ge-0/2/0.0 is selected as the client interface, interface ge-0/2/1.0 transitions to the master state. If interface ge-0/2/1.0is selected as the client port, interface ge-0/2/0.0 transitions to the listening state. You can also configure the interface ge-0/1/4.0 as a client only interface for PTP over Ethernet, if necessary, for completeness of the configuration.
Configuration
In this example, you configure a master port, a client port, and a dynamic port for PTP over Ethernet and PTP over IPv4 encapsulation. You can also configure unicast and multicast modes of transmission of PTP traffic among the master and client nodes.
- CLI Quick Configuration
- Configuring PTP over Ethernet for Multicast Master, Slave, and Dynamic Ports
- Results
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:
set interfaces ge-0/1/4 description “to base-station” set interfaces ge-0/1/4 unit 0 family inet address 7.1.1.37/24 set interfaces ge-0/2/0 description “to MX2” set interfaces ge-0/2/0 unit 0 family inet address 110.1.1.2/24 set interfaces ge-0/1/4 description “to ACX2” set interfaces ge-0/1/4 unit 0 family inet address 110.1.1.2/24 set protocols ptp clock-mode boundary set protocols ptp domain 110 set protocols ptp slave interface ge-0/2/0.0 unicast-mode transport ipv4 set protocols ptp slave interface ge-0/2/0.0 unicast-mode clock-source 110.1.1.250 local-ip-address 110.1.1.2 set protocols ptp master interface ge-0/1/4.0 multicast-mode transport ieee-802.3 set protocols ptp stateful interface ge-0/2/1.0 multicast-mode transport ieee-802.3
Configuring PTP over Ethernet for Multicast Master, Slave, and Dynamic Ports
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 the master, client, and dynamic interfaces, and a boundary clock with unicast and multicast mode of transmission of PTP packets in PTP over IPv4 and PTP over Ethernet topologies:
Configure the master interface, and enter edit mode for the interface.
[edit interfaces] user@host#edit ge-0/1/4
Configure a description for the interface.
[edit interfaces ge-0/1/4] user@host#set description to base-station
Configure a logical unit and specify the protocol family.
[edit interfaces ge-0/1/4] user@host#set unit 0 family inet
Specify the address for the logical interface
[edit interfaces ge-0/1/4 unit 0 family inet] user@host#set address 7.1.1.37/24
Configure the client interface, and enter edit mode for the interface.
[edit interfaces] user@host#edit ge-0/2/0
Configure a description for the interface.
[edit interfaces ge-0/2/0] user@host#set description to-MX2
Configure a logical unit and specify the protocol family.
[edit interfaces ge-0/2/0] user@host#set unit 0 family inet
Specify the address for the logical interface
[edit interfaces ge-0/2/0 unit 0 family inet] user@host#set address 110.1.1.2/24
Configure the stateful interface, and enter edit mode for the interface.
[edit interfaces] user@host#edit ge-0/2/1
Configure a description for the interface.
[edit interfaces ge-0/2/1] user@host#set description to-ACX2
Configure a logical unit and specify the protocol family.
[edit interfaces ge-0/2/1] user@host#set unit 0 family inet
Specify the address for the logical interface
[edit interfaces ge-0/2/1 unit 0 family inet] user@host#set address 110.2.1.1/24
Configure the clock mode as boundary clock.
[edit protocols ptp] user@host# set clock-mode boundary
Specify the PTP domain value.
[edit protocols ptp] user@host# set domain 110
Configure the local client interface from which the boundary master receives time and passes it on to the configured clock clients.
[edit protocols ptp] user@host# edit slave interface ge-0/2/0.0
Configure the upstream unicast PTP master clock source parameters.
[edit protocols ptp slave interface ge-0/2/0.0] user@host# edit unicast-mode
Configure the encapsulation type for PTP packet transport.
[edit protocols ptp slave interface ge-0/2/0.0 unicast-mode] user@host# set transport ipv4
Configure the PTP master parameters by specifying the IP address of the PTP master clock and the IP address of the local interface.
[edit protocols ptp slave interface ge-0/1/0.0 unicast-mode] user@host# set clock-source 110.1.1.250 local-ip-address 110.1.1.2
Configure the master interface in this example.
[edit protocols ptp] user@host# edit master interface ge-0/1/4.0
On the master interface, configure multicast transmission for downstream PTP clock clients.
[edit protocols ptp master interface ge-0/1/4.0] user@host# edit multicast-mode
On the master interface, configure the encapsulation type as Ethernet for PTP packet transport.
[edit protocols ptp master interface ge-0/2/1.0 multicast-mode] user@host# set transport ieee-802.3
Configure the dynamic or stateful interface in this example.
[edit protocols ptp] user@host# edit stateful interface ge-0/2/1.0
On the dynamic interface, configure multicast transmission for downstream PTP clock clients.
[edit protocols ptp stateful interface ge-0/2/1.0 ] user@host# edit multicast-mode
On the dynamic interface, configure the encapsulation type as Ethernet for PTP packet transport and the link-local multicast address to be used.
[edit protocols ptp stateful interface ge-0/2/1.0 multicast-mode] user@host# set transport ieee-802.3 link-local
Results
In 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.
[edit protocols ptp]
user@host# show
clock-mode boundary;
domain 110;
slave {
interface ge-0/2/0.0 {
unicast-mode {
transport ipv4;
clock-source 110.1.1.250 local-ip-address 110.1.1.2;
}
}
}
master {
interface ge-0/1/4.0 {
multicast-mode {
transport ieee-802.3;
}
}
}
stateful {
interface ge-0/2/1.0 {
multicast-mode {
transport ieee-802.3 link-local;
}
}
}
After you have configured the device, enter the commit command in configuration mode.
Verifying the PTP over Ethernet Multicast Dynamic, Master, and Slave Settings
Confirm that the configuration is working properly.
- Verifying the PTP Clock Details
- Verifying the Lock Status of the Slave
- Verifying the PTP Options on the Slave
- Verifying the PTP Options and the Current Status of the Master
- Verifying the Number and Status of the PTP Ports
- Verifying PTP Statistics
Verifying the PTP Clock Details
Purpose
Verify that the PTP clock is working as expected.
Action
In operational mode, enter the run show ptp clock command to display comprehensive, globally configured clock details.
Meaning
The output displays the clock details, such as the
encapsulation method used for transmission of PTP traffic and the
number of configured stateful or dynamic ports. Although a dynamic
port functions as either a client or a master port, the value displayed
in the Stateful Ports field denotes
the dynamic ports that you explicitly configured. The number of dynamic
ports is not computed and displayed in the fields that display the
explicitly configured master and client ports. For more information
about the run show ptp clock operational command, see show ptp clock in the CLI Explorer.
Verifying the Lock Status of the Slave
Purpose
Verify that the client clock is aligned to the master clock by checking the lock status of the client.
Action
In operational mode, enter the run show ptp lock-status command to display the lock status of the client.
Meaning
The output displays information about the lock status
of the client. The output shows whether the client is aligned to
the master clock or not, and the interface name configured for PTP
on the client. The Master Source Port field displays the address of the master clock when PTP over IPv4
is configured and the multicast MAC address of the source when PTP
over Ethernet is configured. For more information about the run
show ptp lock-status operational command, see show ptp lock-status in the CLI Explorer.
Verifying the PTP Options on the Slave
Purpose
Verify the PTP options that are set on the client and the current status of the master.
Action
In operational mode, enter the run show ptp slave command to display the configured client.
Meaning
The output displays information about the configured
client and the status of the client. For more information about the show ptp slave operational command, see show ptp slave in the CLI Explorer.
Verifying the PTP Options and the Current Status of the Master
Purpose
Verify the PTP options that are set for the master and its current status.
Action
In operational mode, enter the run show ptp master command to display the configured options for the master.
Meaning
The output displays information about the configured
master and the current status of the master. For more information
about the run show ptp master operational command, see show ptp master in the CLI Explorer.
Verifying the Number and Status of the PTP Ports
Purpose
Verify the number of PTP ports and their current status.
Action
In operational mode, enter the run show ptp port command to display the configured ports.
Meaning
The output displays information about the number of
ports created according to the configuration and their current status.
The name of the interface configured for PTP and the number of times
a stateful port transitioned from the client to the master state and
vice versa is displayed. For more information about the run show
ptp port operational command, see show ptp port in the CLI Explorer.
Verifying PTP Statistics
Purpose
Verify the statistical details of the PTP configuration.
Action
In operational mode, enter the run show ptp statistics command to display the statistical information regarding the configured
PTP clocks.
Meaning
The output displays brief or detailed information about
the operation of configured PTP clocks. Statistical parameters include
information such as the total number of PTP packets transmitted or
received by a master or client interface and the number of various
messages (such as announce and synchronization messages) that are
sent between a master and a client. For more information about the show ptp statistics operational command, see show ptp statistics in the CLI Explorer.