Configuring Span - Cisco Catalyst 4500 series Administration Manual

Chapter 58 Configuring SPAN and RSPAN

Configuring SPAN

The following sections describe how to configure SPAN:
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Note Entering SPAN configuration commands does not clear previously configured SPAN parameters. You
must enter the no monitor session command to clear configured SPAN parameters.
SPAN Configuration Guidelines and Restrictions
Follow these guidelines and restrictions when configuring SPAN:
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OL_28731-01
SPAN Configuration Guidelines and Restrictions, page 58-7
Configuring SPAN Sources, page 58-8
Configuring SPAN Destinations, page 58-9
Monitoring Source VLANs on a Trunk Interface, page 58-9
Configuration Scenario, page 58-10
Verifying a SPAN Configuration, page 58-10
You must use a network analyzer to monitor interfaces.
You cannot mix source VLANs and filter VLANs within a SPAN session. You can have source
VLANs or filter VLANs, but not both at the same time.
EtherChannel interfaces can be SPAN source interfaces; they cannot be SPAN destination interfaces.
When you specify source interfaces and do not specify a traffic type (Tx, Rx, or both), "both" is used
by default. To change from both to either "tx" or "rx," unconfigure the corresponding other type "rx"
or "tx" with the no monitor session {session_number} {source {interface interface_list | {vlan
vlan_IDs | cpu [queue queue_ids] } {rx | tx} command.
If you specify multiple SPAN source interfaces, the interfaces can belong to different VLANs.
You must enter the no monitor session number command with no other parameters to clear the
SPAN session number.
The no monitor command clears all SPAN sessions.
SPAN destinations never participate in any spanning tree instance. SPAN includes BPDUs in the
monitored traffic, so any BPDUs seen on the SPAN destination are from the SPAN source.
SPAN is limited to one destination port per session.
When you create a SPAN session, it sets the packet filter to good automatically and hence you will
see another configuration line:
monitor session 1 filter packet-type good rx
Software Configuration Guide—Release IOS XE 3.6.0E and IOS 15.2(2)E
Configuring SPAN
58-7