Switch Port Analyzer (SPAN)

With the Switch Port Analyzer (SPAN) page, you can:

• Enable port monitoring.

By enabling the Switch Port ANalyzer (SPAN), you can monitor traffic on a port by forwarding incoming and outgoing traffic to another port. You can use a network analyzer on the monitor port to troubleshoot network problems by examining traffic on other ports or segments.

You can designate any port as the monitor port, but the following restrictions apply:

• A monitor port must be a static-access port.
• A monitor port cannot be in a Fast EtherChannel or Gigabit EtherChannel port group.
• An ATM port cannot be a monitor port but can be monitored.
• A monitor port cannot be enabled for port security.
• A monitor port cannot be a multi-VLAN port.
• A monitor port must be a member of the same VLAN as the port monitored. VLAN membership changes are disallowed on monitor ports and ports being monitored.
• In Enterprise Edition Software only, a monitor port cannot be a dynamic-access port or a trunk port. However, a static-access port can monitor a VLAN on a trunk port. The VLAN monitored is the one associated with the static-access port.

Enabling Port Monitoring

To enable one port to monitor traffic on another port:

1. In the Monitor Ports column, select the port or ports to be the monitor ports.
2. In the Ports Being Monitored columns, select the ports to be monitored.
   Note: You can select only 15 ports before you click Apply. If you want more than 15 ports, select them in groups of 15 or less and then click Apply.
   Port selection is limited to ports that belong to the same VLAN, and you might see some ports displayed without check boxes.
3. Click Apply.