When configuring the routing platform, you can configure the transmit clock on each interface; the transmit clock aligns each outgoing packet transmitted over the routing platform’s interfaces. For both the routing platform and interfaces, the clock source can be the routing platform’s internal Stratum 3 clock, which resides on the control board, or an external clock that is received from the interface you are configuring. For example, interface A can transmit on interface A’s received clock (external, loop timing) or the Stratum 3 clock (internal, line timing). Interface A cannot use a clock from any other source.
By default, each interface uses the routing platform’s internal Stratum 3 clock. To configure the clock source of each interface, include the clocking statement at the [edit interfaces interface-name] hierarchy level:
- [edit interfaces interface-name]
-
clocking (internal
| external);
Figure 5 illustrates the different clock sources.
Figure 5: Clock Sources
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