Cisco Systems OL-7396-01 Manual De Usuario

To configure where each interface receives its transmit clocking, perform the following steps, beginning 
in global configuration mode:

If the Network Clock Distribution Protocol (NCDP) is running on an interface, you should not override 
that port’s clock source by configuring it to free-running or loop-timed. Doing so could cause 
synchronization problems, particularly in the case of loop-timed, which could cause a clocking loop to 
be formed on a link. See the 

The following example configures ATM interface 3/0/0 to receive its transmit clocking from a 
network-derived source:

Switch(config)# interface atm 3/0/0

Switch(config-if)#

To show the switch’s network clocking configuration, use the following privileged EXEC commands:

The following example shows the configured network clock sources on a Catalyst 8510 MSR or 
LightStream 1010:

Switch# show network-clocks

clock configuration is NON-Revertive

Priority 1 clock source: ATM1/0/0

Priority 2 clock source: ATM1/1/0

Priority 3 clock source: No clock

Priority 4 clock source: No clock

Priority 5 clock source: System clock

Current clock source:System clock, priority:5

A source listed as “No clock” indicates that no clock source configured at that priority.

Switch(config)# interface atm card/subcard/port

Switch(config-if)#

Selects the interface to be configured.

Switch(config-if)# clock source {free-running | 
loop-timed | network-derived}

Configures the interface clock source.

Shows the network clocking configuration. 

Shows the interface clock source configuration. 

show controllers [atm card/subcard/port]

Shows the interface controller status.