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Catalyst 3550 Multilayer Switch Software Configuration Guide
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Chapter15 Configuring SPAN Configuring SPAN
This example shows how to disable received traffic monitoring on por t 1, whi ch was co nfigu re d for
bidirectional monitoring:
Switch(config)# no monitor session 1 source interface gigabitethernet0/1 rx
The monitoring of traffic received on port 1 is disabled, bu t t raffic sent from t his po rt c on tinu es to be
monitored.
Specifying VLANs to Monitor
VLAN monitoring is similar to port monitoring. Beginning in privileged EXEC mode, follow these steps
to specify VLANs to monitor:
To remove one or more source VLANs or destination ports from the SPAN session, use the no monitor
session session_number source vlan vlan-id global configuration command or t he no mo nitor se ssion
session_number destination interface interface-id global configuration command.
Command Purpose
Step1 configure terminal Enter global configuration mode.
Step2 no monitor session session_number Clear any existing SPAN configuration for the session.
For session_number, specify 1 or 2.
Step3 monitor session session_number source
vlan vlan-id [, | -] rx Specify the SPAN session and the source VLANs (monitored VLANs).
You can monitor only received (rx) traffic on VLANs.
For session_number, specify 1 or 2.
For vlan-id, the range is 1 to 1005.
(Optional) Use a comma (,) to specify a series of VLANs, or use a
hyphen (-) to specify a range of VLANs. Enter a space after the comma;
enter a space before and after the hyphen.
Step4 monitor session session_number
destination interface interface-id
[encapsulation {dot1q | isl}]
Specify the SPAN session and the destination port (monitoring port).
For session_number, specify 1 or 2.
For interface-id, specify the destination port. Valid interfaces include
physical interfaces.
(Optional) Specify the encapsulation header for outgoing packets. If
not specified, packets are sent in native form.
islUse ISL encapsulation.
dot1qUse 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.