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Catalyst 2940 Switch Software Configuration Guide
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Chapter20 Configuring SPAN Configuring SPAN
This example shows how to set up a SPAN session, session 1, for monitoring source port traffic to a
destination port. First, any existing SPAN configuration for session 1 is cleared, and then bidirectional
traffic is mirrored from source port 1 to destination port 10.
Switch(config)# no monitor session 1
Switch(config)# monitor session 1 source interface fastEthernet0/1
Switch(config)# monitor session 1 destination interface fastEthernet0/10
encapsulation dot1q
Switch(config)# end
Step3 monitor session session_number source
interface interface-id [, | -] [both | rx | tx]Specify the SPAN session and the source port (monitored port).
For session_number, specify 1.
For interface-id, specify the source port to monitor. Valid interfaces
include physical interfaces and port-channel logical interfaces
(port-channel port-channel-number).
(Optional) [, | -] Specify a series or range of interfaces. Enter a space
before and after the comma; enter a space before and after the
hyphen.
(Optional) Specify the direction of traffic to monitor. If you do not
specify a traffic direction, the source interface sends both sent and
received traffic.
both—Monitor both received and sent traffic.
rx—Monitor received traffic.
tx—Monitor sent traffic.
Step4 monitor session session_number
destination interface interface-id
[encapsulation {dot1q}]
Specify the SPAN session and the destination port (monitoring port).
For session_number, specify 1.
For interface-id, specify the destination port. Valid interf aces include
physical interfaces.
(Optional) Specify the encapsulation header for outgoing packets. If
not specified, packets are sent in native form.
dot1q—Use 802.1Q encapsulation.
Step5 end Return to privileged EXEC mode.
Step6 show monitor [session session_number] Verify your entries.
Step7 copy running-config startup-config (Optional) Save your entries in the configuration file.
Command Purpose