Configuring Precision Time Protocol
You can configure the primary clock and the client clock for Precision Time Protocol (PTP) to help synchronize clocks in a distributed system. This time synchronization is achieved through packets that are transmitted and received in a session between the primary clock and the client clock.
Configuring PTP Options
To configure PTP options:
- In configuration mode, go to the
[edit protocols ptp]hierarchy level:[edit] user@host# edit protocols ptp
- Configure the clock mode as either boundary or ordinary.
This attribute is mandatory and has no default value.
The
boundaryoption signifies that the clock can be both a primary clock and a client clock. Theordinaryoption signifies that the clock is either a primary clock or a client clock.[edit protocols ptp] user@host# set clock-mode (boundary | ordinary)
- Configure the PTP domain option with values from 0 through
127. The default value is 0.
[edit protocols ptp] user@host# set domain domain-value
- Configure the
priority1option with values from 0 through 254. The default value is 128.The
priority1value determines the best primary clock. The priority1-value is also advertised in the primary clock’s announce message to other slaves.[edit protocols ptp] user@host# set priority1 priority1-value
- Configure the
priority2option with values from 0 through 255. The default value is 128.The
priority2value differentiates and prioritizes the primary clock to avoid confusion whenpriority1-valueis the same for different primary clocks in a network.[edit protocols ptp] user@host# set priority2 priority2-value
- Configure the
unicast-negotiationoption to enable unicast negotiation.Unicast negotiation is a method by which the announce, sync, and delay response packet rates are negotiated between the primary clock and the client clock before a PTP session is established.
[edit protocols ptp] user@host# set unicast-negotiation
Note:Unicast negotiation, when enabled, does not allow you to commit any packet rate–related configuration.
Configuring Member Clock Options
Configure the following options after the aforementioned PTP options have been set.
- Configure the client clock.
[edit protocols ptp] user@host# edit slave
- Configure the
announce-timeoutoption in the client node with values from 2 through 10. The default value is 3.The announce timeout value signifies the number of times an announce interval message has to pass through the client without receiving the announce message—that is, the timeout period for announce messages.
[edit protocols ptp slave] user@host# set announce-timeout announce-timeout-value
- Configure the
delay-requestoption in the client node with values from –6 through 6. The default value is –4.The delay request value is the logarithmic mean interval in seconds between the delay request messages sent by the client to the primary.
[edit protocols ptp slave] user@host# set delay-request delay-request-value
- Configure the
frequency-onlyoption to enable only frequency synchronization in the client.[edit protocols ptp slave] user@host# set frequency-only
Note:This option is configured only when PTP is used for frequency synchronization and not for phase synchronization. Also, note that this option can only be set for an ordinary clock acting as client.
- Configure the interface for the client.
[edit protocols ptp slave] user@host# edit interface interface-name
- Configure the
unicast-modeoption for the client. You can set this option when PTP unicast mode of messaging is needed.[edit protocols ptp slave interface interface-name] user@host# edit unicast-mode
- Configure the
transportoption in unicast mode as IPv4.The encapsulation type for PTP packet transport is IPv4.
[edit protocols ptp slave interface interface-name unicast-mode] user@host# set transport ipv4
- Configure the IP address of the client.
[edit protocols ptp slave interface interface-name unicast-mode] user@host# edit clock-source ip-address
- Configure the IP address of the interface acting as the
local PTP client port.
[edit protocols ptp slave interface interface-name unicast-mode clock-source ip-address] user@host# set local-ip-address local-ip-address
Note:You must configure this IP address at the [
edit interfaces interface-name] hierarchy level. - You can configure PTP over IPv4 over a link aggregation
group for MPC2E NG, MPC3E NG, MPC5E, MPC6E, MPC7E-10G, MPC7E-MRATE,
MPC8E, and MPC9E.
For each aggregated Ethernet link configured as PTP client, you can specify one member link of the aggregated Ethernet bundle as primary and another as secondary.
[edit protocols ptp slave interface interface-name ] user@host# set primary interface-name user@host# set secondary interface-name
- Starting in Junos
OS Release 15.2R1, you can configure multicast mode option for the
client port. In this mode, PTP over Ethernet
uses multicast addresses and a client port can automatically start
receiving the multicast announce messages transmitted by the primary
ports on a network. The client port can start communicating with the
primary port with minimal or no configuration.
[edit protocols ptp slave interface interface-name ] user@host#
set multicast-mode - Configure Ethernet as the encapsulation type of transport
for the PTP packets. You can further enable 802.3 Ethernet encapsulation
to use a specific set of multicast MAC addresses while transmitting
the PTP packets over Ethernet.
[edit protocols ptp slave interface interface-name multicast-mode] asymmetry number; transport 802.3 link-local;
Note:It is mandatory to use the
transportstatement while configuring the multicast-mode for primary and client interfaces. - You can configure PTP over Ethernet over a link aggregation group for
MPC5E, MPC6E, MPC7E-10G, MPC7E-MRATE, MPC8E, MPC9E, and MPC10E line
cards.
For each aggregated Ethernet link configured as PTP client, you can specify one member link of the aggregated Ethernet bundle as primary and another as secondary.
[edit protocols ptp slave interface interface-name ] user@host# set primary interface-name user@host# set secondary interface-name
Configuring Primary Clock Options
Configure the following options after the aforementioned PTP options and client clock options have been set.
- Configure the primary clock.
[edit protocols ptp] user@host# edit master
- Configure the
announce intervaloption for the primary with values from 0 through 4. The default value is 1.The announce interval is the logarithmic mean interval between announce messages that is sent by the primary. By default, one announce message is sent in every two seconds.
[edit protocols ptp master] user@host# set announce-interval announce-interval-value
- Configure the
clock stepoption as either one-step or two-step for the primary. The default value is one-step.The clock step determines whether the timing information is sent along with the sync message only (one-step) or a subsequent follow-up message (two-step) is sent corresponding to the previous sync message.
[edit protocols ptp master] user@host# set clock-step (one-step | two-step)
- Configure the
sync intervaloption for the primary clock with values from –6 through 6. The default value is –6.The sync interval is the logarithmic mean interval between synchronous messages that is sent by the primary. By default, 64 synchronous interval messages are sent per second.
[edit protocols ptp master] user@host# set sync-interval sync-interval-value
- Configure the interface for the primary.
[edit protocols ptp master] user@host# edit interface interface-name
- Configure the unicast mode option for the primary. You
can set this option when PTP unicast mode of messaging is needed.
[edit protocols ptp master interface interface-name] user@host# edit unicast-mode
- Configure the
transportoption in unicast mode as IPv4.The encapsulation type for PTP packet transport is IPv4.
[edit protocols ptp master interface interface-name unicast-mode] user@host# set transport ipv4
- Configure the IP address for the client.
[edit protocols ptp master interface interface-name unicast-mode] user@host# edit clock-client ip-address
- Configure the IP address of the interface acting as the
local PTP primary port.
[edit protocols ptp master interface interface-name unicast-mode clock-client ip-address] user@host# set local-ip-address local-ip-address
- You can configure PTP over IPv4 over a link aggregation
group for MPC2E NG, MPC3E NG, MPC5E, MPC6E, MPC7E-10G, MPC7E-MRATE,
MPC8E, and MPC9E.
For each aggregated Ethernet link configured as PTP primary, you can specify one member link of the aggregated Ethernet bundle as primary and another as secondary.
[edit protocols ptp master interface interface-name ] user@host# set primary interface-name user@host# set secondary interface-name
- Starting with
Junos OS Release 15.2R1, you can configure multicast mode option for
the primary port. In this mode, PTP over Ethernet
uses multicast addresses and a client port can automatically start
receiving the multicast announce messages transmitted by the primary
ports on a network. The client port can start communicating with the
primary port with minimal or no configuration.
[edit protocols ptp master interface interface-name ] user@host#
set multicast-mode - Configure Ethernet as the encapsulation type of transport
for the PTP packets. You can further enable 802.3 Ethernet encapsulation
to use a specific set of multicast MAC addresses while transmitting
the PTP packets over Ethernet.
[edit protocols ptp master interface interface-name multicast-mode] asymmetry number; transport 802.3 link-local;
Note:It is mandatory to use the
transportstatement while configuring the multicast-mode for primary and client interfaces. - You can configure PTP over Ethernet over a link aggregation group for
MPC5E, MPC6E, MPC7E-10G, MPC7E-MRATE, MPC8E, MPC9E, and MPC10E line
cards.
For each aggregated Ethernet link configured as PTP primary, you can specify one member link of the aggregated Ethernet bundle as primary and another as secondary.
[edit protocols ptp master interface interface-name ] user@host# set primary interface-name user@host# set secondary interface-name
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