Specifications

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Cisco MGX 8800/8900 Series Software Configuration Guide
Release 5.1, Part Number OL-6482-01, Rev. A0, January 25, 2005
Chapter 9 Switch Operating Procedures
Managing Manually Configured Clocks Sources
mgx8830a.1.PXM.a > dspclksrcs
The following example shows a display with neither primary nor secondary clocks configured. This is
the default configuration of a switch, which uses the internal clock as the network clock source.
Whenever the active clock is listed as null, the switch is using the internal clock.
mgx8830a.1.PXM.a > dspclksrcs
Primary clock type: null
Primary clock source: 0.0
Primary clock status: not configured
Primary clock reason: okay
Secondary clock type: null
Secondary clock source: 0.0
Secondary clock status: not configured
Secondary clock reason: okay
Active clock: internal clock
source switchover mode: non-revertive
In the following example, the display shows that both the primary and secondary clocks are configured
for network clock sources. The primary clock source is coming from port 1 on the PXM1E card in slot
1. The primary clock source is active. The secondary clock source is coming from port 1 on the CESM
card in slot 6.
mgx8830a.1.PXM.a > dspclksrcs
Primary clock type: generic
Primary clock source: 1:2.2:1
Primary clock status: ok
Primary clock reason: okay
Secondary clock type: generic
Secondary clock source: 6:1.1:1
Secondary clock status: ok
Secondary clock reason: okay
Active clock: primary
source switchover mode: non-revertive
Reconfigure Manual Clock Sources
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:
• To reconfigure a clock source for a BITS clock, see the “Configuring the MPLS Controller” section
in Chapter 2, “Configuring General Switch Features.”
• To reconfigure a clock source to use a PXM1E line, see the “Configuring PXM1E Line Clock
Sources” section in Chapter 3, “Provisioning PXM1E Communication Links.”
• To reconfigure a clock source to use a AXSM line, see refer to the Cisco ATM Services (AXSM)
Configuration Guide and Command Reference for MGX Switches, Release 5.
When reconfiguring a clock source from primary to secondary or from secondary to primary, you must
delete both existing clock sources and define new clock sources. The switch will not allow you to create
two primary or two secondary clock sources, and the switch will not allow you to configure the same
line as both primary and secondary clock sources. After you have deleted the old clock source, you can
use the appropriate procedure to define a new clock source.
To delete a clock source, enter the delclksrc command as described in the next section.