Editing Port mirroring (section)

{{Short description|Network switch feature for monitoring traffic}}
{{No footnotes|date=April 2014}}

'''Port mirroring ''' is used on a [[network switch]] to send a copy of [[computer network|network]] [[Packet (information technology)|packets]] seen on one switch [[Port (computer networking)|port]] (or an entire [[VLAN]]) to a [[network monitoring]] connection on another switch port. This is commonly used for network appliances that require monitoring of network traffic such as an [[intrusion detection system]], [[Passive probing|passive probe]] or [[real user monitoring]] (RUM) technology that is used to support [[application performance management]] (APM). Port mirroring on a [[Cisco Systems]] switch is generally referred to as ''Switched Port Analyzer'' (SPAN) or ''Remote Switched Port Analyzer'' (RSPAN). Other vendors have different names for it, such as ''Roving Analysis Port'' (RAP) on [[3Com]] switches.

Network engineers or administrators use port mirroring to analyze and [[debug]] data or diagnose errors on a network. It helps administrators keep a close eye on network performance and alerts them when problems occur. It can be used to mirror either inbound or outbound traffic (or both) on single or multiple [[network interface controller|interfaces]].