LLDP-EXT-DOT1-MIB

MIB Reference — IPNetwork Monitor · Updated September 09, 2026

All MIBsLLDP-EXT-DOT1-MIB

Organization: IEEE 802.1 Working Group

Last Updated: 2005-05-06

Category: Protocol: LLDP, Standard: IEEE 802

Description: IEEE 802.1 LLDP extension MIB defining Type-Length-Value (TLV) objects for 802.1-specific information including VLAN and port protocol.

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.

What Is LLDP-EXT-DOT1-MIB?

LLDP-EXT-DOT1-MIB is the IEEE 802.1 organizationally-specific extension to the standard LLDP-MIB, defining TLV objects that carry 802.1-specific discovery information such as VLAN and protocol identification between directly connected network devices. It exposes configuration tables controlling which 802.1 TLVs (port VLAN, VLAN name, protocol VLAN, and protocol identity) are transmitted on each port, along with local data reflecting what is advertised to neighbors. Its monitoring value is largely software/configuration status for topology and VLAN discovery—confirming which VLAN and protocol information a port advertises via LLDP, which helps detect VLAN trunking mismatches between neighboring switches. It explicitly depends on and extends the base IEEE 802.1AB LLDP-MIB, from which it branches via an OUI-based OID. It is deployed on any vendor-neutral, standards-based switch or router implementing IEEE 802.1AB LLDP with 802.1 extensions in enterprise and campus networks. Most enterprise NMS platforms support LLDP-EXT-DOT1-MIB SNMP polling out of the box, since it is a standard IEEE extension rather than a proprietary vendor module.

IPNetwork Monitor allows you to monitor SNMP objects defined in LLDP-EXT-DOT1-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
  • any IEEE 802.1AB LLDP-capable switch or router

Monitoring Examples

An admin would poll lldpXdot1ConfigPortVlanTable's lldpXdot1ConfigPortVlanTxEnable to confirm whether a port is configured to advertise its VLAN ID via LLDP, and cross-reference lldpXdot1ConfigVlanNameTable's lldpXdot1ConfigVlanNameTxEnable to verify VLAN name advertisement is enabled for troubleshooting VLAN mismatches between neighbors. The lldpXdot1ConfigProtoVlanTable and lldpXdot1ConfigProtocolTable (with their respective TxEnable objects) would be checked to confirm which protocol VLAN and protocol identity TLVs are being sent, useful when diagnosing why a neighboring switch is not learning the expected VLAN/protocol topology.

What Can Be Monitored

  • port VLAN TLV transmission enable
  • VLAN name TLV transmission enable
  • protocol VLAN TLV transmission enable
  • protocol identity TLV transmission enable
Imported Objects

From LLDP-MIB

lldpExtensionsOBJECT-IDENTITY
lldpLocPortNumOBJECT-TYPE
lldpPortConfigEntryOBJECT-TYPE
lldpRemIndexOBJECT-TYPE
lldpRemLocalPortNumOBJECT-TYPE
lldpRemTimeMarkOBJECT-TYPE

From Q-BRIDGE-MIB

VlanId

From SNMP-FRAMEWORK-MIB

SnmpAdminString

From SNMPv2-CONF

MODULE-COMPLIANCE
OBJECT-GROUP

From SNMPv2-SMI

Integer32
MODULE-IDENTITY
OBJECT-TYPE

From SNMPv2-TC

TruthValue
OIDs

FAQ

How can LLDP-EXT-DOT1-MIB help troubleshoot a VLAN trunking mismatch between neighboring switches?
It exposes per-port configuration showing which 802.1 TLVs (port VLAN, VLAN name, protocol VLAN, protocol identity) each switch is set to transmit via LLDP, along with local data reflecting what is actually advertised to neighbors. By polling this on both ends of a link, an operator can compare the advertised VLAN and protocol information and spot cases where a trunk port isn't advertising the VLAN details the neighbor expects, which often points to a misconfigured VLAN trunk.

Why would a monitoring platform poll LLDP-EXT-DOT1-MIB in addition to the base LLDP-MIB?
The base LLDP-MIB only carries generic neighbor-discovery information, while LLDP-EXT-DOT1-MIB (branched from lldpExtensions via an OUI) adds the IEEE 802.1-specific TLVs for VLAN and protocol discovery. Since it's a standard IEEE extension rather than a proprietary module, most enterprise NMS platforms can poll it out of the box on any 802.1AB-compliant switch or router to get topology and VLAN discovery detail beyond what plain LLDP provides.

RFC description

IEEE 802.1 extension to Link Layer Discovery Protocol, providing VLAN name and protocol VLAN information discovery across network ports.

Start monitoring Vendor-neutral IEEE 802.1AB LLDP extension (any 802.1AB-capable switch/router) 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 LLDP-EXT-DOT1-MIB