Licensing Requirements and Limitations for Loopback Detection
Involved Network Elements
Other network elements are not required.
Licensing Requirements
Loopback detection is a basic function of the switch, and as such is controlled by the license for basic software functions. The license for basic software functions has been loaded and activated before delivery. You do not need to manually activate it.
Version Requirements
Product Model |
Minimum Version Required |
|---|---|
CE12804/CE12808/CE12812 |
V100R001C00 |
CE12816 |
V100R003C00 |
CE12804S/CE12808S |
V100R005C00 |
CE12800E (configured with FD-X series cards) |
V200R005C00 |
For details about the mapping between software versions and switch models, see the Hardware Query Tool.
Software version evolution: V100R001C00 -> V100R002C00 -> V100R003C00 -> V100R003C10 -> V100R005C00 -> V100R005C10 -> V100R006C00 -> V200R001C00 -> V200R002C50 -> V200R003C00 -> V200R005C00 -> V200R005C10 -> V200R019C00 -> V200R019C10
Feature Limitations
LBDT needs to send a large number of detection packets to detect loops, occupying system resources. Therefore, disable LBDT if loops do not need to be detected.
LBDT is a ring network protocol that conflicts with ring network functions such as Smart Link, ERPS, and STP/RSTP/MSTP/VBST. You are advised not to configure these ring network functions on an LBDT-enabled interface. In contrary, if these ring network functions are configured, disable LBDT on the interface.
In V100R005C00 and earlier versions, LBDT cannot be configured on an Eth-Trunk or its member interfaces.
- When two or more LBDT-enabled interfaces are added to the same VLAN, if loops occur on the network, the hwLdtPortLoop alarm may be frequently generated or cleared on some interfaces, and MAC address flapping may occur between these interfaces. In this case, you are advised to configure the interfaces to enter the Error-Down state or manually check the network to eliminate loops after an alarm is generated.