Specifying Vlans To Monitor - Cisco WS-C3550-12G Software Configuration Manual

Chapter 15 Configuring SPAN
This example shows how to disable received traffic monitoring on port 1, which was configured for
bidirectional monitoring:
Switch(config)# no monitor session 1 source interface gigabitethernet0/1 rx
The monitoring of traffic received on port 1 is disabled, but traffic sent from this port continues 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:
Command
Step 1 configure terminal
Step 2
no monitor session session_number
Step 3 monitor session session_number source
vlan vlan-id [, | -] rx
Step 4 monitor session session_number
destination interface interface-id
[encapsulation {dot1q | isl}]
Step 5
end
Step 6 show monitor [session session_number]
Step 7 copy running-config startup-config
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 the no monitor session
session_number destination interface interface-id global configuration command.
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Purpose
Enter global configuration mode.
Clear any existing SPAN configuration for the session.
For session_number, specify 1 or 2.
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.
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.
• isl—Use ISL encapsulation.
• dot1q—Use 802.1Q encapsulation.
Return to privileged EXEC mode.
Verify your entries.
(Optional) Save your entries in the configuration file.
Catalyst 3550 Multilayer Switch Software Configuration Guide
Configuring SPAN
15-11