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Cisco IE 2000 Switch Software Configuration Guide
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Configuring PTP

Finding Feature Information

Your software release may not support all the features documented in this chapter. For the latest feature
information and caveats, see the release notes for your platform and software release.
Use Cisco Feature Navigator to find information about platform support an d Cisco software image
support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on
Cisco.com is not required.

Prerequisites for Configuring PTP

To use this feature, the switch must be PTP-capable. Refer to your switch rel ease notes.

Restrictions for Configuring PTP

To use this feature, the switch must be running the LAN Base image.

Information About Configuring PTP

Precision Time Protocol

The IEEE 1588 standard describes the use of PTP for fault-tolerant synchronization of network real-t ime
clocks.
The clocks in a PTP network are organized into a master-slave hierarchy. The grandmaster clock is called
the Best Master Clock (BMC), and is the root of the master-slave clock hierarchy. PTP uses the BMC
algorithm to identify the master clock for synchronization.
The master clock is a time source on the network that can be synchronized to a highly accurate time source
such as a Global Positioning System (GPS) clock. The slaves are the other network devices that synchronize
their clocks to the master clock. The parent is the clock to which the member-slave clocks synchronize.
Timing messages between the master and slave clocks ensure continued synchronization.