IEEE8021-Q-BRIDGE-MIB

MIB Reference — IPNetwork Monitor · Updated September 09, 2026

All MIBsIEEE8021-Q-BRIDGE-MIB

Organization: IEEE 802.1 Working Group

Last Updated: 2018-06-28

Category: Standard: IEEE 802, Technology: Switching/L2, Technology: VLAN, VLAN and Bridging

Description: IEEE 802.1 MIB for 802.1Q VLAN bridging providing comprehensive VLAN configuration, filtering, and port membership management.

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What Is IEEE8021-Q-BRIDGE-MIB?

IEEE8021-Q-BRIDGE-MIB is the official IEEE 802.1Q standards-track MIB module (derived from IETF RFC 4363's Q-BRIDGE-MIB) for managing Virtual Bridged Local Area Networks, i.e., VLAN-capable Ethernet switches. It exposes configuration and state data for VLAN bridge components, including per-bridge VLAN capacity and version information, per-port VLAN membership and tagging (C-VLAN) settings, and protocols like MVRP (Multiple VLAN Registration Protocol) enablement. While primarily a configuration-oriented MIB, it also surfaces operational status such as the number of active VLANs, maximum supported VLANs, and MVRP registration state, which administrators use to verify a switch's VLAN database is healthy and within capacity limits rather than hardware environmental health. Because the IEEE8021-Q-BRIDGE-MIB MIB is a formal IEEE standard, its object definitions are consistent across switch vendors that implement 802.1Q. It is explicitly layered on top of, and cross-references, the IETF BRIDGE-MIB (RFC 4188) and Q-BRIDGE-MIB lineage, and depends on standard bridge/port index conventions shared across 802.1D/802.1Q implementations. It is deployed broadly across enterprise and carrier Ethernet switches from any vendor implementing 802.1Q VLAN bridging, typically polled by network management systems to audit VLAN provisioning and detect misconfiguration.

IPNetwork Monitor allows you to monitor SNMP objects defined in IEEE8021-Q-BRIDGE-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

  • vendor-neutral, standards-based MIB, not tied to a specific manufacturer
  • 802.1Q VLAN-capable Ethernet switch/bridge

Monitoring Examples

An administrator would poll ieee8021QBridgeTable/ieee8021QBridgeEntry to read ieee8021QBridgeNumVlans against ieee8021QBridgeMaxSupportedVlans to see how close a switch is to running out of VLAN capacity, and check ieee8021QBridgeMvrpEnabledStatus to confirm dynamic VLAN registration is active where expected. The ieee8021QBridgeCVlanPortTable/ieee8021QBridgeCVlanPortEntry rows let an operator verify which customer VLAN (C-VLAN) a given port is mapped to, useful for diagnosing a port that isn't passing traffic on the expected VLAN. A mismatch between ieee8021QBridgeVlanVersionNumber across stacked switches can also reveal inconsistent VLAN database synchronization.

What Can Be Monitored

  • active VLAN count vs. maximum supported
  • VLAN database version number
  • MVRP registration enabled status
  • per-port C-VLAN membership mapping
  • bridge component identification
Imported Objects

From IEEE8021-BRIDGE-MIB

ieee8021BridgeBasePortOBJECT-TYPE
ieee8021BridgeBasePortComponentIdOBJECT-TYPE
ieee8021BridgeBasePortEntryOBJECT-TYPE

From IEEE8021-TC-MIB

IEEE8021BridgePortNumber
IEEE8021BridgePortNumberOrZero
IEEE8021PbbComponentIdentifier
IEEE8021PortAcceptableFrameTypes
IEEE8021VlanIndex
IEEE8021VlanIndexOrWildcard
ieee802dot1mibsOBJECT-IDENTITY

From Q-BRIDGE-MIB

PortList
VlanId

From RMON2-MIB

TimeFilter

From SNMP-FRAMEWORK-MIB

SnmpAdminString

From SNMPv2-CONF

MODULE-COMPLIANCE
OBJECT-GROUP

From SNMPv2-SMI

Counter64
Gauge32
Integer32
MODULE-IDENTITY
OBJECT-TYPE
TimeTicks
Unsigned32

From SNMPv2-TC

MacAddress
RowStatus
StorageType
TruthValue
OIDs

FAQ

What does IEEE8021-Q-BRIDGE-MIB let me check on a VLAN switch?
It exposes per-bridge VLAN capacity and version data, per-port VLAN membership and C-VLAN tagging settings, and MVRP (Multiple VLAN Registration Protocol) enablement state. This lets you confirm a switch's VLAN database is healthy and within its supported capacity rather than looking at hardware environmental readings.

How would a network team use this MIB to catch VLAN misconfiguration?
Because it's an IEEE 802.1Q standards-track module derived from IETF RFC 4363's Q-BRIDGE-MIB, it works the same way across any vendor's 802.1Q-capable switch. An NMS can poll active VLAN count against the maximum supported, check per-port VLAN membership mappings, and verify MVRP registration state to audit VLAN provisioning and flag misconfigured or over-capacity switches across a mixed-vendor Ethernet network.

RFC description

Defines managed objects for IEEE 802.1Q Virtual LANs (VLAN) and bridge operations as standardized in RFC 4363, covering VLAN classification, multicast forwarding, and traffic filtering on bridged networks.

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Download IEEE8021-Q-BRIDGE-MIB