Switch Port Analyzer (SPAN)

With the Switch Port Analyzer (SPAN) window, 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 not allowed on monitor ports and ports being monitored.
• 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. On the Switch Port Analyzer (SPAN) window, select a port from which monitoring will be done.
2. Click Modify to display the Modify the Ports Being Monitored dialog box.
3. From the Available Ports list, select the port to be monitored.
   To select several ports, hold down the Ctrl key and select individual ports, or hold down the Shift key and select the first and last ports in a range.
4. Click Add to move your selection to the Ports Monitored list.
   To remove ports from this list, highlight the ports and click Remove. The ports are returned to the end of the Available Ports list.
5. Click OK to put your changes in effect and close the Modify the Ports Being Monitored dialog box.
6. Click OK to close the Switch Port Analyzer (SPAN) window.