How to analyze traffic with SPAN feature

Usually when we admin a network, we need to know what are the protocols used more frequently, and why not, discover if someone are using improper P2P software; so we can use SPAN. The Switched Port Analyzer (SPAN) feature, which is sometimes called port mirroring or port monitoring, selects network traffic for analysis by a network analyzer. For example, if you want to capture Ethernet traffic that is sent between host A and host B, you must implement SPAN feature. In this diagram, the sniffer is attached to a port (destination SPAN port) that is configured to receive a copy of [...]