display loopback-detect interface

Function

display loopback-detect interface command displays the LBDT configuration and status of LBDT-enabled interfaces.

Format

display loopback-detect interface interface-type interface-number

Parameters

Parameter	Description	Value
interface-type interface-number	Specifies the interface type and number.	-

Views

All views

Default Level

1: Monitoring level

Usage Guidelines

This command is used to check the loopback detection configuration and status of each interface on which loopback detection is enabled.

Example

# Display the LBDT configuration and status of interfaces that are enabled with LBDT manually.

<HUAWEI> display loopback-detect interface GigabitEthernet 0/0/1
LBDT mode   : Manual
Detect VLAN : Untag
Looped VLAN : 
Action      : shutdown
Status      : NORMAL
Recover Time: 15

# Display the LBDT configuration and status of interfaces that are enabled with LBDT automatically.

<HUAWEI> display loopback-detect interface GigabitEthernet 0/0/1
LBDT mode    : Auto
PVID VLAN    :
  VLAN ID           : 1
  Trap only VLAN ID : -
Mac-flap VLAN:
  Total NUM         : 0
  VLAN ID           : -
  Trap only VLAN NUM: 0
  Trap only VLAN ID : -
  Quit-vlan VLAN NUM: 0
  Quit-vlan VLAN ID : -

**Table 1** Description of the **display loopback-detect interface** command output
Item	Description
LBDT mode	Mode in which LBDT is enabled: Manual: LBDT is enabled manually. To enable LBDT on an interface, run the loopback-detect enable (interface view) command. Auto: LBDT is enabled automatically. To enable automatic LBDT on the device, run the undo loopback-detect auto disable command.
Detect VLAN	VLAN where LBDT is configured to detect loops. To configure a VLAN where LBDT is configured to detect loops, run the loopback-detect packet vlan command.
Looped VLAN	VLAN where loops are detected.
Action	Action performed when a loopback is detected on an interface: block: blocks the interface. After the interface is blocked, it is isolated from other interfaces and does not forward received data packets to other interfaces. nolearn: disables MAC address learning on the interface. When a loopback is detected on the interface, the interface stops learning MAC addresses. shutdown: shuts down the interface. When a loopback is detected on an interface, the interface is shut down. trap: only sends a trap. When a loopback is detected on an interface, the interface only sends a trap. quitvlan: quits VLANs. When a loopback is detected on an interface, the interface exits from the VLAN in which a loop occurs. To configure an action performed when a loopback is detected, run the loopback-detect action command.
Status	Status of a loopback detection enabled interface: NORMAL: No loopback is detected on the interface. BLOCK: A loopback is detected on the interface and the interface is blocked. NOLEARN: A loopback is detected on the interface and the MAC address learning is disabled on the interface. SHUTDOWN: A loopback is detected on the interface and the interface is shut down. TRAP: A loopback is detected on the interface and a trap is sent. QUITVLAN: A loopback is detected on the interface and the interface exits from the VLAN in which a loop occurs.
Recover Time	Restoration time of an interface, in seconds. To configure the restoration time of an interface, run the loopback-detect recovery-time command.
PVID VLAN	VLAN that is specified by the PVID and where automatic LBDT is enabled.
VLAN ID	Default VLAN of the interface. To configure the default VLAN of an interface, run the port default vlan command.
Trap only VLAN ID	VLAN that is specified by the PVID and where loops are detected. The value is displayed as - if there is no such a VLAN.
Mac-flap VLAN	VLAN where MAC address flapping detection is enabled automatically.
Total NUM	Total number of VLANs where MAC address flapping detection is enabled automatically to detect MAC address flapping.
VLAN ID	List of VLANs where MAC address flapping detection is enabled automatically to detect MAC address flapping.
Trap only VLAN NUM	Total number of VLANs where MAC address flapping detection is enabled automatically to detect MAC address flapping and the action is trap.
Trap only VLAN ID	List of VLANs where MAC address flapping detection is enabled automatically to detect MAC address flapping and the action is trap.
Quit-vlan VLAN NUM	Total number of VLANs where MAC address flapping detection is enabled automatically to detect MAC address flapping and the action is quit-vlan.
Quit-vlan VLAN ID	List of VLANs where MAC address flapping detection is enabled automatically to detect MAC address flapping and the action is quit-vlan.