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Precision Time Protocol is used to synchronize clocks throughout the network. On a local area network, it achieves clock accuracy in the sub-microsecond range, making it suitable for measurement and control systems. RouterOS supports IEEE 1588-2008, PTPv2. Support is hardware dependant, please see the supported device list below.

Supported features:

  • Boundary/Ordinary clock
  • E2E delay mode
  • PTP delay mode
  • UDP over IPv4 multicast transport mode
  • L2 transport mode
  • priority1 can be configured to decide master/slave
  • PTP clock IS NOT synced with the system clock

General properties

Sub-menu: /system ptp

portSub-menu used for adding, removing, or viewing assigned ports
statusSub-menu that shows PTP ports, their state, and delay on slave ports
comment (string; Default: )

Short description of the PTP profile

name (string; Default: )Name of the PTP profile
delay-mode (auto | e2e | ptp; Default: auto)Configures delay mode for PTP profile
    • auto - selects delay mode automatically
    • e2e - use the delay request-response mechanism
    • ptp - use the peer delay mechanism
priority1 (integer [0..255]; auto; Default: auto)the priority value for influencing grandmaster election
profile (802.1as; default; g8275.1; Default: default)

IEEE 1588-2008 includes a profile concept defining PTP operating parameters and options. 

IEEE 802.1AS is an adaptation of PTP for use with Audio Video Bridging and Time-Sensitive Networking. Uses delay-mode=p2p, transport-mode=l2; recommends using priority1=auto.

g8275.1 profile is for frequency and phase synchronization in a fully PTP-aware network. Only allows priority1=auto (128), priority2=128, domain=24, delay-mode=e2e, transport=l2.

default profile, PTPv2 default configuration, allows for more configuration options than other profiles, but default values with auto settings correspond to: priority1=128. priority2=128, domain=0,transport=ipv4, delay-mode=e2e

transport (auto; ipv4;  l2; Default: auto)transport protocol to be used: IPv4 or layer2

For more details regarding Precision Time Protocol please see the following standards IEEE 1588 and IEEE 802.1as.

We strongly recommend keeping default/auto values, as there are different requirements between profiles. And assigning them manually can result in misconfiguration.


To configure the device to participate in PTP you first need to create a PTP profile:

/system ptp add name=ptp1
#to view the created profile use
/system ptp print 
Flags: I - inactive, X - disabled 
0 name="ptp1" priority1=auto delay-mode=auto transport=auto profile=default


Only 1 PTP profile is supported per device

After creating a PTP profile, you need to assign ports to it:

/system ptp port add interface=ether1 ptp=ptp1
#to view assigned ports use
/system ptp port print 
Flags: I - inactive 
0 ptp=ptp1 interface=ether8 

1 ptp=ptp1 interface=ether22 

To monitor the PTP profile, use the monitor command:

#on grandmaster device
[admin@grandmaster] > system ptp monitor numbers=0
name: test
clock-id: 64:D1:54:FF:FE:EB:AE:C3
priority1: 30
priority2: 128
i-am-gm: yes

#on non-grandmaster device
[admin@328] /system ptp monitor 0
name: ptp1
clock-id: 64:D1:54:FF:FE:EB:AD:C7
priority1: 128
priority2: 128
i-am-gm: no
gm-clock-id: 64:D1:54:FF:FE:EB:AE:C3
gm-priority1: 30
gm-priority2: 128
master-clock-id: 64:D1:54:FF:FE:EB:AE:C3
slave-port: ether8
freq-drift: 2147483647 ppb
offset: 1396202830 ns
hw-offset: 1306201921 ns
slave-port-delay: 2075668440 ns

Monitor properties

clock-id:local clock ID
priority1:priority1 value, depending on the PTP profile selected, an adjustable value used to influence the grandmaster election.
priority2:priority2 value, non-adjustable in RouterOS
i-am-gm: yes | noshows if the device is a grandmaster clock
gm-clock-id:grandmaster clock ID - Within a domain, a clock that is the ultimate source of time for clock synchronization using the protocol. 
gm-priority1:grandmaster priority1
gm-priority2:grandmaster priority2
master-clock-id:master clock ID - In the context of a single Precision Time Protocol (PTP) communication path, a clock that is the source of time to which all other clocks on that path synchronize. 
slave-port:shows which port is going towards the master or grandmaster clock
freq-drift:frequency drift in PPB (parts per billion) - time that would be lost every second in relation to the master clock, IF there was no synchronization.
offset:difference between clock values
hw-offset:offset difference from the hardware clock
slave-port-delay:the time it takes for a packet to be delivered to a directly connected device

Device support

Supported on:
CRS326-24G-2S+ supported only on Gigabit Ethernet ports
CRS328-24P-4S+ supported only on Gigabit Ethernet ports
CRS317-1G-16S+ supported on all ports
CRS326-24S+2Q+ supported on SFP+ and QSFP+ interfaces
CRS312-4C+8XG supported on all ports
CRS318-16P-2S+ supported only on Gigabit Ethernet ports
Not supported on:

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