Which configuration allows a router or switch to make a copy of every packet it processes?

The correct choice, which involves SPAN or Mirrored Port, is the configuration that enables a switch or router to make a copy of every packet it processes. SPAN stands for Switched Port Analyzer, and it is a feature used on network switches to mirror traffic from one port to another. By configuring SPAN, network administrators can monitor, analyze, and troubleshoot network traffic without interrupting the flow of data.

When SPAN is activated on a specific port, any packets sent or received on that port are duplicated and sent to the designated monitoring port. This is especially useful for network analysis tools like intrusion detection systems (IDS) or network performance monitoring tools, as they can review the mirrored traffic for potential issues or security threats.

Traffic mirroring, while often used interchangeably with SPAN, is a broader term that can refer to different methods of duplicating traffic, but in the context of specific configurations relevant to switches, SPAN is the most accurate answer. Load balancers distribute network or application traffic across multiple servers or resources, thus not tailored for packet duplication specifically. Internal Border Gateway Protocol (iBGP) is a routing protocol used within autonomous systems and does not pertain to packet mirroring functionalities.