VLAN-MIB

MIB Reference — IPNetwork Monitor · Updated October 06, 2026

All MIBs › VLAN-MIB

Organization: FORE

Last Updated: 1999-11-05

Category: VLAN and Layer 2 Switching

Description: Manages FORE Systems ATM VLAN emulated LAN memberships and bridge port associations.

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What Is VLAN-MIB?

This is a pre-standards IEEE 802.1Q VLAN MIB from FORE Systems for devices implementing ATM LAN Emulation (LEC), predating the ratified 802.1Q standard. It exposes a VLAN configuration table (name, ID, type, creator, row status) along with associations to port groups, MAC address lists, protocol types, and IP subnets used to classify traffic into VLANs. Its monitoring value is chiefly configuration/software status: the row status of each VLAN entry shows whether a VLAN configuration is active or stuck mid-creation/deletion, and the port-group/MAC-list associations confirm actual VLAN membership is consistent with intent. It is explicitly tied to the pre-standard IEEE 802.1Q draft and to ATM LAN Emulation Client (LEC) concepts rather than to the final ratified VLAN bridging standard. It is deployed on FORE Systems ATM switches/edge devices that bridge LAN segments together over an ATM backbone using LAN Emulation. Network engineers evaluating or troubleshooting this functionality can download the VLAN-MIB file directly to load it into their MIB browser.

IPNetwork Monitor allows you to monitor SNMP objects defined in VLAN-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

  • FORE Systems ATM switches with LAN Emulation (LEC)

Monitoring Examples

An admin would poll vlanConfTable indexed by vlanID to check vlanConfRowStatus and vlanName - a VLAN stuck in a non-active row status indicates a failed configuration commit - while vlanPortGroupInstance and vlanMacListInstance reveal which ports/MAC addresses are currently mapped to a VLAN, and vlanProtocolType/vlanProtocolSubtype or vlanIPSubnetAddress show whether the VLAN is classified by protocol or IP subnet, useful for diagnosing misclassified traffic.

What Can Be Monitored

  • VLAN configuration/name/ID
  • VLAN row status
  • VLAN creator
  • port group membership
  • MAC list membership
  • protocol/subnet-based VLAN classification
Imported Objects

From Fore-Common-MIB

preDot1qVlanMIBOBJECT-IDENTITY

From SNMPv2-SMI

Integer32
IpAddress
MODULE-IDENTITY
OBJECT-TYPE

From SNMPv2-TC

DisplayString
MacAddress
RowStatus
TestAndIncr
OIDs

RFC description

Pre-standards IEEE 802.1Q VLAN management MIB for Fore systems ATM switches with LAN emulation support.

Start monitoring FORE Systems ATM switches with LAN Emulation (LEC) (pre-standard VLAN config/row-status 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.

Download VLAN-MIB