What is a span port?

A span port, often referred to as a port mirror, is a feature on network switches that allows traffic on one or more ports to be copied and sent to a designated monitoring port. This is useful for network analysis and troubleshooting, as it enables tools like packet analyzers or intrusion detection systems to monitor the data flow without disrupting the network. By mirroring the traffic, administrators can observe real-time data without affecting the performance of the original traffic streams.