CLI Reference Guide-R02

Chapter 15 | Loopback Detection Commands
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loopback-detection This command enables loopback detection globally on the switch or on a specified
interface. Use the no form to disable loopback detection.
Syntax
[no] loopback-detection
Default Setting
Enabled
Command Mode
Global Configuration
Interface Configuration (Ethernet, Port Channel)
Command Usage
◆ Loopback detection must be enabled globally for the switch by this command
and enabled for a specific interface for this function to take effect.
◆ Loopback detection cannot be enabled globally if ingress filtering of any port
whose loopback detection is enabled cannot be enabled.
◆ Loopback detection cannot be enabled for a port if ingress filtering cannot be
enabled.
◆ When loopback detection is enabled globally and for a port, the ingress
filtering of the port is automatically enabled. The ingress filtering setting is
restored after loopback detection is disabled globally or for the port.
Example
This example enables general loopback detection on the switch, disables loopback
detection provided for the spanning tree protocol on port 1, and then enables
general loopback detection for that port.
Console(config)#loopback-detection
Console(config)#interface ethernet 1/1
Console(config-if)#loopback-detection
Console(config)#
loopback-detection
action
This command specifies the protective action the switch takes when a loopback
condition is detected. Use the no form to restore the default setting.
Syntax
loopback-detection action {none | shutdown}
no loopback-detection action