Cisco router CSU/DSU configuration If your router is functioning as a CSU/DSU and you want to provide a 64,000 bps serial link, which command must you enter?

Introduction / Context:
When a Cisco router provides clocking on a serial connection (acting as a CSU/DSU), the clock rate command is required to set the data rate on the interface. This is typically used in lab environments or DCE (Data Communications Equipment) configurations.

Given Data / Assumptions:

• The router is providing DCE clocking.
• Speed required = 64,000 bps (64 kbps).
• Command must be entered in interface configuration mode.

Concept / Approach:

The clock rate command configures the DCE interface's clock speed. The value is entered in bits per second. For 64,000 bps, the correct command is clock rate 64000.

Step-by-Step Solution:

Verification / Alternative check:

Cisco IOS reference guides confirm clock rate 64000 as the proper syntax for a 64 kbps link.

Why Other Options Are Wrong:

• bandwidth 64 or 64000: sets bandwidth metric, not actual clocking.
• clock rate 64: incorrect unit (bps vs kbps).
• set speed: not a valid Cisco IOS command.

Common Pitfalls:

• Confusing bandwidth (informational for routing protocols) with clock rate (actual line speed).

Final Answer:

RouterA(config-if)#clock rate 64000