Can a box switch record logs and alarms after a loop detection-enabled interface detects a loop

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A fixed switch can record alarms but not logs after a loop detection-enabled interface detects a loop. The configurations are as follows:
In V100R005 and V100R006, you can run the snmp-agent trap enable feature-name ldttrap command to enable the alarm function for loop detection. If snmp-agent trap enable has been configured globally, the alarm function has been enabled.

Loop detection and loopback detection have been available since V200R001. You can run the snmp-agent trap enable feature-name ldttrap command to enable the alarm function for loop detection and run the snmp-agent trap enable feature-name lbdt command to enable the alarm function for loopback detection.

You can run the display trapbuffer command to view alarms.

Other related questions:
Will logs be generated when loops are detected on S series switch' interfaces where loopback detection is enabled
Logs and alarms will be generated after loops are detected on modular switches' interfaces where loopback detection is enabled. To view the related alarms, run the display trapbuffer command. Only alarms will be generated after loops are detected on interfaces of fixed switches (except S1700). To view the related alarms, run the display trapbuffer command.

Whether loop detection can be configured on the firewall interface
The USG2000&5000&6000 do not support configuring the loop detection command at the interface. Loop detection usually applies to detection at the lower-layer switches. On the firewall: 1. You can make a comparison by viewing interface traffic information. If the traffic volumes of certain interfaces are large and similar, a loop may occur. 2. If a loop occurs, the following alarm information is displayed. Alarm information: PPP/4/TRAP: [oid] Interface (IfIndex:[interface-index]) LoopBack is detected

Loop prevention and breaking on S series switch
For S series switches except S1700 switches, use any of the following methods to remove loops: 1. Configure features such as STP, RSTP, MSTP, VBST,RRPP, and SEP to prevent loops. 2. Bundle dual physical links into a single logical link to prevent loops while implementing redundancy and increasing bandwidth. 3. Configure the switch to transparently transmit packets of different VLANs along different paths. 4. Enable loop detection and loopback detection to detect loops on the switch or downstream network connected to the switch, and configure the switch to take the preconfigured action to remove loops. Fixed switches only support loopback detection.

Can S series switches be configured not to take any action after a loop is detected
Huawei S series (except the S1700) and E series switches performs the configured default action after detecting a loop, that is, shutting down interfaces. The action can be changed but cannot be disabled. When the action is changed to trap, the switches only report traps and do not take any other action after detecting a loop. Command used to configure the action performed on an interface after LDT detects a loop: loop-detection mode { port-trap | port-blocking | port-nolearning | port-shutdown | port-quitvlan } Command used to configure the action performed on an interface after LBDT detects a loop: loopback-detect action { block | nolearn | shutdown | trap | quitvlan } Note: For S series switches, the port-quitvlan and quitvlan actions are supported in V200R002 and later versions.

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