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Cisco IE 2000 Switch Software Configuration Guide
OL-25866-01
Chapter 8 Configuring PTP
How to Configure PTP
Synchronization behavior depends on the PTP clock setting mode that you configure on the switch. The
mode can be boundary, end-to-end transparent, or forward:
• A switch clock in boundary mode participates in the selection of the most accurate master clock. If
more accurate clocks are not detected, that switch clock becomes the master cloc k. If a more
accurate clock is found among the slave clocks, then the swi tch synchronizes to that clock and
becomes a slave clock. After initial synchronization, the switch and the connected devices exchange
timing messages to correct the changes caused by clock offsets and network delays.
• A switch clock in end-to-en d transparent mode synchronizes all switch ports with the master clock.
This switch does not participate in master clock selection a nd uses the default PTP clock mode on
all ports.
• A switch clock in forward mode allows incoming PTP packets to pass-through the switch as normal
multicast traffic.
When the switch is in PTP forward mode, PTP configuration is not available except when changing PTP
mode to another mode. You can only configure per-port PTP when the switch is in boundary mode.
How to Configure PTP
• Default PTP Settings, page 8-2
• Setting Up PTP, page 8-3

Default PTP Settings

By default, PTP is enabled on all the Fast Ethernet and Gigabit Ethernet ports on the base switch module.
The default PTP mode on all ports is end-to-end transparent.
Tab l e 8-1 Default PTP Settings
Feature Default Setting
PTP boundary mode Disabled.
PTP forward mode Disabled.
PTP end-to-end transparent mode Enabled.
PTP priority 1 and PTP priority 2 Default priority number is 128.
PTP announce interval 2 seconds.
PTP announce receipt time out 3 messages.
PTP delay request interval 32 seconds.
PTP sync interval 1 second.
PTP sync limit 500000000 nanoseconds.