What is SPAN in Cisco?
Cisco Catalyst Switches have a feature called SPAN (Switch Port Analyzer) that lets you copy all traffic from a source port or source VLAN to a destination interface. If you want to use wireshark to capture traffic from an interface that is connected to a workstation, server, phone or anything else you want to sniff.
How does SPAN port work?
A SPAN port (sometimes called a mirror port) is a software feature built into a switch or router that creates a copy of selected packets passing through the device and sends them to a designated SPAN port. Using software, the administrator can easily configure or change what data is to be monitored.
How does span work Cisco?
Switch port Analyzer (SPAN) is an efficient, high performance traffic monitoring system. It duplicated network traffic to one or more monitor interfaces as it transverse the switch. SPAN is used for troubleshooting connectivity issues and calculating network utilization and performance, among many others.
What is span capture?
How to capture network traffic: Port mirroring. Port mirroring, also known as SPAN or roving analysis, is a method of monitoring network traffic which forwards a copy of each incoming and/or outgoing packet from one (or several) port(s) (or VLAN) of a switch to another port where the analysis device is connected.
What is span used for in networking?
SPAN (Switched Port Analyzer) is a dedicated port on a switch that takes a mirrored copy of network traffic from within the switch to be sent to a destination. The destination is typically a monitoring device, or other tools used for troubleshooting or traffic analysis.
What is the difference between tap and span?
A tap is a purpose-built device that passively makes a copy of network data but does not alter the data. SPAN ports, also called mirror ports, are part of Layer 2 and 3 network switches. They are active devices and will require you to program them to copy the data desired.
What does span stand for in Cisco switchprobe?
The SPAN feature, which is sometimes called port mirroring or port monitoring, selects network traffic for analysis by a network analyzer. The network analyzer can be a Cisco SwitchProbe device or other Remote Monitoring (RMON) probe.
How is span traffic affected by VLAN filtering?
When a VLAN filter list is specified, only those VLANs in the list are monitored on trunk ports or on voice VLAN access ports. SPAN traffic coming from other port types is not affected by VLAN filtering, which means that all VLANs are allowed on other ports.
Why was the span feature introduced in catalyst?
The SPAN feature was introduced on switches because of a fundamental difference that switches have with hubs. When a hub receives a packet on one port, the hub sends out a copy of that packet on all ports except on the one where the hub received the packet.