CISCOSB-LBD-MIB

Description: Manages Cisco Small Business Loopback Detection (LBD) for identifying and disabling looped switch ports.

Start monitoring vendor-neutral, standards-based MIB, any SNMPv3-capable network device (SNMP engine identity/boot/clock status) with a free 30-day trial of IPNetwork Monitor. Import MIBs, browse SNMP OIDs, create custom SNMP monitors, configure alerts, and monitor any SNMP-enabled network device from a single console.

CISCOSB-LBD-MIB is a Cisco Small Business enterprise MIB for the Loopback Detection (LBD) feature, which identifies Ethernet ports that are looped back to themselves or to another switch, creating broadcast storms. It exposes configuration and per-interface operational data, including a global enable flag, the loop-detection polling interval, the detection mode, and the administrative status forced on an interface when a loop is detected. Its primary monitoring value is software/feature status: confirming that loop detection is active, how frequently it probes for loops, and whether a specific port has been automatically shut down (its admin status changed) in response to a detected loop condition. It relies on standard Interfaces MIB conventions (ifIndex/ifAdminStatus) to identify and act on the physical ports involved. It is typically used on Cisco Small Business (SG/SF series) switches in small-office/branch deployments to protect the network from accidental cable loops without requiring full Spanning Tree Protocol analysis. Engineers can download the CISCOSB-LBD-MIB file directly to load it into their MIB browser.

An administrator polls rlLbdEnable to confirm the feature is globally active and checks rlLbdDetectionInterval and rlLbdMode to verify how the switch is configured to probe for loops. If a user accidentally connects two ports on the same switch (or two switches) with a patch cable, the switch detects the loop and updates rlLbdIfAdminStatus for the affected interface to a disabled state, which the NMS can catch to alert on an automatically shut-down port. Re-polling rlLbdIfAdminStatus after the cable is removed confirms whether the port needs to be manually re-enabled.

Enables loopback detection on Cisco Small Business switches to prevent bridging loops with configurable detection intervals and modes.