Specifications

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Cisco MGX 8850 (PXM45) and MGX 8950 Software Configuration Guide
Release 3, Part Number 78-14788-01 Rev. C0, January 2004
Chapter 7 Switch Operating Procedures
Managing Manually Configured Clocks Sources
Step 3 To delete a clock source, enter the delclksrc command.
mgx8850a.7.PXM.a > delclksrc <priority>
The following example deletes a primary clock source.
mgx8850a.7.PXM.a > delclksrc primary
Step 4 To verify that a clock source has been deleted, enter the dspclksrcs command. When the primary or
secondary clock source is deleted, the clock type is set to null.
Restore a Clock Source After Failure
The procedure you use to reconfigure a clock source depends on whether or not you need to change the
role of the clock source. If the clock source keeps its role as either primary or secondary, just enter a new
cnfclksrc command as described in the following locations:
The revertive option for clock sources connected to the PXM45 allows a primary clock source to resume
operation as the primary clock source after a failure and restoration of the clock signal. However, if you
have the revertive option disabled, or if your primary clock source is connected to an AXSM line, you
will have to reconfigure the primary clock source after it is restored. To reconfigure the clock source as
a BITS clock source, see the “Configuring Clock Sources” section in Chapter 2, “Configuring General
Switch Features.” To reconfigure the clock source as a AXSM line clock source, see the “Configuring
AXSM Line Clock Sources” section in Chapter 6, “Provisioning AXSM Communication Links.”
Tip Enter the dspclksrcs command to display the current configuration settings for the primary clock source.
Having this information available makes it easier to re-enter the cnfclksrc command.
Note To change a clock source on the PXM45 from nonrevertive to revertive, enter the cnfclksrc with the
option –revertive enable.
When the primary clock source is restored on the master clock node, you may have to reconfigure the
primary clock source at each remote node where the node has switched from the primary source to the
secondary source. This reconfiguration is necessary only if the local node has detected a change in the
master clock source.
To determine if you need to reconfigure the primary clock at a nonmaster node, enter the dspclksrcs
command. If the active clock has changed to either secondary or internal clock, you must use the
cnfclksrc command to reconfigure the primary clock source for that node.