A3COM00xx-BRIDGE-EXT-MIB

MIB Reference — IPNetwork Monitor · Updated October 05, 2026

All MIBs › A3COM00xx-BRIDGE-EXT-MIB

Category: VLAN Management

Description: Extends IEEE 802.1D bridging objects with 3Com proprietary port and forwarding controls.

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What Is A3COM00xx-BRIDGE-EXT-MIB?

This MIB extends IEEE 802.1D bridging with 3Com-proprietary GARP/GMRP/GVRP and VLAN forwarding controls on 3Com switches. It exposes per-port GARP/GMRP/GVRP administrative and operational status, GARP timer settings (join/leave/leave-all time), and single-forwarding-database status alongside base 802.1Q VLAN and extended bridge objects. Its monitoring value lies in comparing admin vs. operational status for GMRP/GVRP per port, which reveals ports where dynamic multicast/VLAN registration has failed to come up despite being enabled, a common source of multicast forwarding problems. It directly extends the standard IETF BRIDGE-MIB and 802.1Q VLAN MIB conventions (dot1dExtended/dot1qVlan). It's deployed on 3Com managed switches running GARP-based dynamic VLAN/multicast registration. Engineers can download the A3COM00xx-BRIDGE-EXT-MIB file directly to load it into their MIB browser.

IPNetwork Monitor allows you to monitor SNMP objects defined in A3COM00xx-BRIDGE-EXT-MIB. Use the built-in SNMP Monitoring Browser to explore available variables, view their current values and descriptions, and select the objects you want to monitor. You can then create SNMP monitors, configure thresholds, and receive alerts when monitored values change.

Supported Devices

  • 3Com managed switches

Monitoring Examples

An operator would compare a3ComPortGmrpAdminStatus against a3ComPortGmrpOperStatus for each a3ComPortGarpEntry in a3ComPortGarpTable to catch a port where GMRP is enabled administratively but not actually operating, explaining multicast traffic not being pruned/forwarded correctly; checking a3ComGarpJoinTime, a3ComGarpLeaveTime, and a3ComGarpLeaveAllTime helps diagnose slow or flapping dynamic VLAN/group membership caused by misconfigured GARP timers.

What Can Be Monitored

  • GMRP/GVRP admin vs operational status per port
  • GARP join/leave/leave-all timers
  • single forwarding database status
  • VLAN/bridge extended configuration
Imported Objects

From A3COM0004-GENERIC

a3ComBridgeExtOBJECT-IDENTITY

From BRIDGE-MIB

MacAddress
Timeout
dot1dBasePortOBJECT-TYPE

From RFC-1212

OBJECT-TYPE
OIDs

RFC description

3Com bridge extensions MIB covering GMRP, GVRP, VLANs, and 802.1d priority configurations.

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Download A3COM00xx-BRIDGE-EXT-MIB