Edge-Core ECS4120-28F, Reference Manual, Page: 475 / 938

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16
Loopback Detection Commands
The switch can be configured to detect general loopback conditions caused by
hardware problems or faulty protocol settings. When When loopback detection
(LBD) is enabled, a control frame is transmitted on the participating ports, and the
switch monitors inbound traffic to see if the frame is looped back.
Usage Guidelines
◆
The default settings for the control frame transmit interval and recover time
may be adjusted to improve performance for your specific environment. The
shutdown mode may also need to be changed once you determine what kind
of packets are being looped back.
◆
General loopback detection provided by the command described in this
section and loopback detection provided by the spanning tree protocol cannot
both be enabled at the same time. If loopback detection is enabled for the
spanning tree protocol, general loopback detection cannot be enabled on the
same interface.
◆
When a loopback event is detected on an interface or when a interface is
released from a shutdown state caused by a loopback event, a trap message is
sent and the event recorded in the system log.
◆
Loopback detection must be enabled both globally and on an interface for
loopback detection to take effect.
Table 93: Loopback Detection Commands
Command Function Mode
loopback-detection Enables loopback detection globally on the switch
or on a specified interface GC, IC
loopback-detection
action Specifies the response to take for a detected
loopback condition GC
loopback-detection
recover-time Specifies the interval to wait before releasing an
interface from shutdown state GC
loopback-detection
transmit-interval Specifies the interval at which to transmit loopback
detection control frames GC
loopback detection trap Configures the switch to send a trap when a
loopback condition is detected or the switch
recover from a loopback GC
loopback-detection
release Manually releases all interfaces currently shut down
by the loopback detection feature PE
show
loopback-detection Shows loopback detection configuration settings
for the switch or for a specified interface PE