> # Configuring Beacon Mode

> By default, the beacon mode is disabled on all switches. The beacon mode is indicated by a flashing green light that helps you identify the physical location of the specified interface. Configuring the beacon mode has no effect on the operation of the interface.

> ## Detailed Steps

> To enable beacon mode for a specified interface or range of interfaces using DCNM-SAN, follow these steps:

> 1. Expand Switches > Ethernet Interfaces > Physical > IPS (the Gigabit Ethernet Interfaces).

> You see the interface configuration in the Information pane.

> 2. Click the Beacon Mode and enable this option for the selected switch.
> 3. Click Apply Changes.

> ## Troubleshooting Tips

> - The flashing green light turns on automatically when an external loopback is detected that causes the interfaces to be isolated. The flashing green light overrides the beacon mode configuration. The state of the LED is restored to reflect the beacon mode configuration after the external loopback is removed.

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