Cisco Catalyst 2360, Руководство по настройке программного обеспечения

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20-4
Catalyst 2360 Switch Software Configuration Guide
OL-19808-01
Chapter 20 Configuring SPAN
Understanding SPAN
ports on the switch) and any number of source VLANs (up to the maximum number of VLANs
supported). However, the switch supports a maximum of two sessions with source ports or VLANs. You
cannot mix ports and VLANs in a single session.
A source port has these characteristics:
•
It can be monitored in multiple SPAN sessions on a switch.
• Each source port can be configured with a direction (ingress, egress, or both) to monitor.
•
It can be any port type (for example, EtherChannel, Gigabit Ethernet, and so forth).
• For EtherChannel sources, you can monitor traffic for the entire EtherChannel or individually on a
physical port as it participates in the port channel.
•
It can be an access port or trunk port.
• It cannot be a destination port.
•
Source ports can be in the same or different VLANs.
• You can monitor multiple source ports in a single session.
Source VLANs
VLAN-based SPAN (VSPAN) is the monitoring of the network traffic in one or more VLANs. The
SPAN source interface in VSPAN is a VLAN ID, and traffic is monitored on all the ports for that VLAN.
VSPAN has these characteristics:
•
All active ports in the source VLAN are included as source ports and can be monitored in either or
both directions.
•
On a given port, only traffic on the monitored VLAN is sent to the destination port.
•
If a destination port belongs to a source VLAN, it is excluded from the source list and is not
monitored.
•
If ports are added to or removed from the source VLANs, the traffic on the source VLAN received
by those ports is added to or removed from the sources being monitored.
•
You cannot use filter VLANs in the same session with VLAN sources.
• You can monitor only Ethernet VLANs.
VLAN Filtering
When you monitor a trunk port as a source port, by default, all VLANs active on the trunk are monitored.
You can limit SPAN traffic monitoring on trunk source ports to specific VLANs by using VLAN
filtering.
•
VLAN filtering applies only to trunk ports.
• VLAN filtering applies only to port-based sessions and is not allowed in sessions with VLAN
sources.
•
When a VLAN filter list is specified, only those VLANs in the list are monitored on trunk ports.
• SPAN traffic coming from other port types is not affected by VLAN filtering; that is, all VLANs are
allowed on other ports.
•
VLAN filtering affects only traffic forwarded to the destination SPAN port and does not affect the
switching of normal traffic.