H3C S9500 Series Command Manual page 1814

Command Manual – Clock Module
H3C S9500 Series Routing Switches
When the original clock source recovers, the clock module will switch to the
original clock source. In this case, the manually set primary clock source will not
work.
If SSM is engaged in control, the clock module will select a clock source by SSM
level first. If two clock sources have the same SSM level, they will be selected by
the priority. If they have the same priority, they will be selected in high-to-low order
from clock source 1 to clock source 18. If the available clock source with highest
SSM level is lost, it will be switched to the next available clock source with the
highest SSM level automatically. When the original clock source recovers, the
clock module will switch back to the original clock source. In this case, the
manually set primary clock source will not work.
3) Clock sources not engaged in switching
The following clock sources are neglected during clock source selection (when SSM is
engaged in control):
Clock sources whose signal is lost are unavailable clock sources, and are not
engaged in switching.
Clock sources with the priority of 0xFF are unconfigured clock sources, and are
not engaged in switching.
Clock sources with the SSM level being DNU should not be used for
synchronization, and are not engaged in switching.
Examples
# Set the work mode of clock module on the SRPU to manual and use the primary clock
source 1.
<H3C> system-view
System View: return to User View with Ctrl+Z.
[H3C] clock manual source 1
# Restore the work mode of clock module to auto.
<H3C> system-view
System View: return to User View with Ctrl+Z.
[H3C]undo clock work-mode
1.1.2 clock forcessm
Syntax
clock forcessm { on | off } source source-no
View
System view
Chapter 1 Clock Module Commands
1-2