Manually Specifying A Reference Clock Source; Establishing The Configuration Task - Huawei Quidway S9300 Configuration Manual

Quidway S9300 Terabit Routing Switch
Configuration Guide - Device Management
Step 2 Run the display clock selection command to view the current clock sources of the external
clocks.
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11.4 Manually Specifying a Reference Clock Source

The S9300 allows you to manually specify a reference clock source flexibly.

11.4.1 Establishing the Configuration Task

Before manually specifying a reference clock source, familiarize yourself with the applicable
environment, complete the pre-configuration tasks, and obtain the required data.
Applicable Environment
When clock sources are configured with priorities but not configured with SSM quality levels,
you can manually specify a clock source if you need to select a clock with a lower priority as
the clock source.
Pre-configuration Tasks
Before manually specifying a clock source, complete the following tasks:
l
l
l
Data Preparation
To manually specify a clock source, you need the following data.
Issue 03 (2011-12-29)
NOTE
You can run either of the preceding commands to check the configuration of forcible clock source selection.
NOTE
l You cannot manually specify a clock source in Signal-fail state.
l When the SSM quality level is used in clock source selection, you cannot specify a clock source whose
SSM quality level is lower than the SSM quality level of the current clock source.
l If the signal of the manually specified clock source becomes invalid or if the SSM quality level of the
clock source degrades, the system automatically enters the free running state. The specified clock source
never takes effect again even if its signal or quality level recovers.
Setting parameters of the link layer protocol and IP addresses for the interfaces to ensure
that the link layer protocol on the interfaces is in Up state
Configuring the routing protocol to make the IP routes between the nodes reachable
Ensuring the clock that will be configured to meet the following conditions:
– All clock sources provide valid clock signals.
– The result of frequency offset check does not affect clock source selection or the
frequency offset of the clock sources is within the specified range.
– The clock sources are not locked.
– The priority of the clock is other than 255 (DIS) so that the clock can function as the
clock source.
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11 Ethernet Clock Syntonization Configuration
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