Port mirroring is used on a
network switch to send a copy of
network packets seen on one switch
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 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
3Com Corporation was an American digital electronics manufacturer best known for its computer network products. The company was co-founded in 1979 by Robert Metcalfe, Howard Charney and others. Bill Krause joined as President in 1981. Metcalfe ex ...
switches.
Network engineers or administrators use port mirroring to analyze and
debug
In computer programming and software development, debugging is the process of finding and resolving '' bugs'' (defects or problems that prevent correct operation) within computer programs, software, or systems.
Debugging tactics can involve int ...
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
interfaces
Interface or interfacing may refer to:
Academic journals
* Interface (journal), ''Interface'' (journal), by the Electrochemical Society
* ''Interface, Journal of Applied Linguistics'', now merged with ''ITL International Journal of Applied Lin ...
.
See also
*
VLAN access control list A VLAN access control list (VACL) provides access control for all packets that are bridged within a VLAN or that are routed into or out of a VLAN. Unlike regular Cisco IOS access control lists that are configured on router interfaces and applied on ...
(VACL)
External links
Cisco Systems - Catalyst Switched Port Analyzer (SPAN) Configuration ExamplePort mirroring (roving analysis port)- TechTarget, 2014
Port Mirroring- Technopedia
Computer network analysis
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