Cisco Systems OL-7396-01 Configuring Network Clock Sources and Priorities (Catalyst 8510 MSR and

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ATM Switch Router Software Configuration Guide
OL-7396-01
Chapter3 Initially Configuring the ATMSw itch Router
Configuring Network Clocking
Systems equipped with the network clock module can derive clocking from a Building Integrated Timing
Supply (BITS) source. To specify the line type attached to the BITS ports on the network clock module
and to assign a priority to a port, use the following commands in global configuration mode:
Examples
The following example shows how to configure the network clock priorities:
Switch(config)# network-clock-select 1 atm 0/0/0
Switch(config)# network-clock-select 2 atm 0/0/3
Note This configuration assumes that a full-width module, such a s the 4-port OC-12c module, is being used
to derive clocking. If port adapters inserted into carrier modules are used, the priority1 and 2 source
ports must be on different port adapters.
The following example shows how to configure the network clock to revert to the highest priority clock
source after a failure and takeover by the source with the next lowest priority.
Switch(config)# network-clock-select revertive
Configuring Network Clock Sources and Priorities (Catalyst 8510 MSR and
LightStream 1010)
To configure the network clocking priorities and sources, use the following command in global
configuration mode:
Note Specifying the keyword system with the network-clock-select command selects the route processor
reference clock (a stratum 4 clock source).
Examples
The following example shows how to configure the network clock priorities:
Switch(config)# network-clock-select 1 atm 0/0/0
Switch(config)# network-clock-select 2 atm 0/0/3
The following example shows how to configure the network clock to revert to the highest priority clock
source after a failure and takeover by the source with the next lowest priority.
Switch(config)# network-clock-select revertive
Command Purpose
network-clock-select bits {t1 | e1} Selects the line type. This command applies to
both BITS ports.
network-clock-select priority bits {0 | 1} Selects the priority for a BITS port.
Command Purpose
network-clock-select {priority {{atm | cbr}
card/subcard/port} | system} | revertive
Configures the network clock priority.