Configuring the TTL for PTP Packets
To set the Time To Live (TTL) of PTP packets, use the ptp ttl command. TTL is the maximum number of hops that a PTP packet may make.
Example
switch(config)# ptp ttl 64
switch(config)#
Configuring PTP Monitoring
PTP monitoring records PTP information including offset from master, mean path delay, and skew values, which can then be viewed using a show command. When this feature is enabled, PTP Syslog messages will also be generated for those metrics for which threshold values have been configured on the switch. PTP monitoring is enabled by default.
Enabling and Disabling PTP Monitoring
Use the ptp monitor command to enable PTP monitoring on the device (it is enabled by default). The no form of the command disables PTP monitoring and clears all the recorded PTP data.
Example
switch(config)# no ptp monitor
Configuring the Offset-from-master Threshold
The offset is the difference in nanoseconds between master and slave time. Use the ptp monitor threshold offset-from-master command to specify the offset-from-master threshold in nanoseconds. A Syslog message is generated if the most recently calculated time offset from the PTP master is outside of the range (-<threshold>, <threshold>). The maximum offset threshold is one second. The no form of the command clears the threshold value and prevents further Syslog messages from being generated for this parameter.
Example
switch(config)# ptp monitor threshold offset-from-master 500
Configuring the Mean-path-delay Threshold
Example
switch(config)# ptp monitor threshold mean-path-delay 2000
Configuring the Skew Threshold
PTP skew is the clock frequency difference between master and slave. Use the ptp monitor threshold skew command to configure the value of the skew-threshold percentage. A Syslog message is generated if the value of the most recently calculated skew is not in the range (1/(1+<threshold>), 1*(1+<threshold>)). Skew threshold percentage is represented a double precision (16 digit) real number ranging from 0 (0%) to 10 (1000%). The no form of the command clears the threshold value and prevents further Syslog messages from being generated for this parameter.
Example
switch(config)# ptp monitor threshold skew 5
Setting the PTP Announce Interval
To set the interval at which an interface sends PTP announce messages, use the ptp announce interval command. The interval is measured in log seconds. This value also affects the timeout interval.
switch(config)# interface ethernet 5
switch(config-if-Et5)# ptp announce interval 2
switch(config-if-Et5)#
Setting the PTP Timeout Interval
To set the timeout multiplier for an interface, use the ptp announce timeout command. The timeout multiplier is the number of announcement intervals that the interface will wait without receiving a PTP announcement before a timeout occurs; values range from 2 to 255. The default multiplier is 3, which results in a 6-second timeout interval when the announcement interval is set to the default of 2 seconds.
switch(config-if-Et5)# ptp announce timeout 5
switch(config-if-Et5)#
Configuring the PTP Delay Mechanism
To set the delay mechanism used in boundary-mode, use the ptp delay-mechanism command.
Example
switch(config-if-Et5)# ptp delay-mechanism p2p
switch(config-if-Et5)#
Setting the Delay Request Interval
To set the time for the slave devices to send delay request messages, use the ptp delay-req interval command.
Example
switch(config-if-Et5)# ptp delay-request interval 3
switch(config-if-Et5)#
Setting the Peer Delay Request Interval
To set the minimum interval between the PTP peer delay-request messages, use the ptp pdelay-req interval command.
Example
switch(config-if-Et5)# ptp pdelay-request interval 3
switch(config-if-Et5)#
Setting the Peer Link Propagation Threshold
To set the delay threshold for which the peer will be considered unable to run generalized Precision Time Protocol (gPTP), use the ptp pdelay-neighbor-threshold command.
Example
switch(config-if-Et5)# ptp pdelay-neighbor-threshold 200000
switch(config-if-Et5)#
Setting the Interval for Sending Synchronization Messages
To set the interval (in log seconds) for sending synchronization messages, use the ptp sync-message interval command. Value ranges and defaults vary based on the PTP mode of the switch.
Example
switch(config-if-Et5)# ptp sync-message interval 3
switch(config-if-Et5)#