Which command effectively monitors traffic flow in networking devices?

The command that effectively monitors traffic flow in networking devices is "show policy-map." This command is primarily used to display and monitor quality of service (QoS) configurations and traffic statistics associated with traffic classes that have been defined in policy maps. When you issue this command, it provides specific details about how traffic is being handled, such as the amount of traffic matched by a specific policy and the effects of the configured policies. This is especially valuable in environments where traffic prioritization and management are critical, as it helps to ensure that the network is performing optimally according to the defined policies.

Other commands listed serve different purposes. For instance, "show ip interface brief" displays a summary of the IP interface status and configuration but does not provide detailed information about traffic flow. "show traffic statistics," while sounding relevant, is not a standard command for monitoring traffic flow in most systems. Lastly, "show process list" is typically used to show active processes running on a device, not related to traffic flow management. Therefore, "show policy-map" is the command that best meets the needs for effective traffic flow monitoring.