Dell-UDLD-MIB

All MIBs › Dell-UDLD-MIB

Organization: Dell

Last Updated: 2012-08-01

Category: Protocol: UDLD, Vendor: Dell

Description: Manages Unidirectional Link Detection (UDLD) to detect one-way link failures on Dell switches.

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What Is Dell-UDLD-MIB?

Dell-UDLD-MIB is a Dell Networking enterprise MIB implementing Unidirectional Link Detection (UDLD), a Layer-2 protocol that detects one-way link failures — where a port can receive but not transmit traffic, or vice versa — that standard link-state monitoring alone can miss. It exposes per-port configuration and state objects (rlUdldPortAdminMode, rlUdldPortOperMode, rlUdldBidirectionalState) plus a neighbor discovery table (rlUdldNeighborTable) tracking detected neighbor device IDs and their ports. It is used to monitor the protocol-level health of switch ports — specifically whether each enabled port's link is confirmed bidirectional or has been flagged unidirectional — which is important for catching cabling or transceiver faults that could otherwise cause forwarding loops or blackholed traffic. It complements standard IEEE link-state and spanning-tree monitoring, referencing IF-MIB ifIndex values for its port identification, though it defines no other strict external MIB dependency. It is typically deployed on Dell switches in enterprise networks with fiber or long-haul copper links, where undetected unidirectional failures pose a loop risk. Engineers can download the Dell-UDLD-MIB file directly to load it into their MIB browser.

IPNetwork Monitor allows you to monitor SNMP objects defined in Dell-UDLD-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

Dell Networking switches

Monitoring Examples

An operator would poll rlUdldPortTable entries such as rlUdldPortAdminMode and rlUdldPortOperMode to confirm UDLD is enabled on a port, then check rlUdldBidirectionalState to see whether that port's link is bidirectional or has been declared unidirectional. Correlating a unidirectional state with rlUdldNeighborTable entries (rlUdldNeighborDeviceID, rlUdldNeighborPortIfIndex) helps pinpoint which physical link and neighboring device is experiencing a one-way fiber/cable fault, prompting a cabling check before it triggers a switching loop.

What Can Be Monitored

per-port UDLD admin/operational mode
port bidirectional link state
detected neighbor count
neighbor device ID and port mapping

Imported Objects

From Dell-MIB

rnd	MODULE-IDENTITY
rndNotifications	OBJECT-IDENTITY

From IF-MIB

InterfaceIndex

From SNMP-FRAMEWORK-MIB

SnmpAdminString

From SNMPv2-CONF

MODULE-COMPLIANCE
NOTIFICATION-GROUP
OBJECT-GROUP

From SNMPv2-SMI

Gauge32
Integer32
MODULE-IDENTITY
NOTIFICATION-TYPE
OBJECT-TYPE
Unsigned32

From SNMPv2-TC

MacAddress
RowStatus
TEXTUAL-CONVENTION
TruthValue

OIDs

OID symbolic	OID numeric	Type	Access	Description
rlUdld	1.3.6.1.4.1.89.218			This private MIB module for UDLD (Cisco Systems UniDirectional Link Detection Protocol).
rlUdldPortTable	1.3.6.1.4.1.89.218.1		not-accessible	The table holds information for Udld Ethernet ports.
rlUdldPortEntry	1.3.6.1.4.1.89.218.1.1		not-accessible	Entry in the rlUdldPortTable.
NUM rlUdldPortIfIndex	1.3.6.1.4.1.89.218.1.1.1	InterfaceIndex	not-accessible	Interface Index. This variable is the key for udld port table. uniquely identifies the udld port information.
UDL rlUdldPortAdminMode	1.3.6.1.4.1.89.218.1.1.2	UdldPortMode	read-write	This variable identifies port UDLD admin configured mode (normal, aggressive, disable).
UDL rlUdldPortOperMode	1.3.6.1.4.1.89.218.1.1.3	UdldPortMode	read-only	This variable identifies port UDLD operational mode (normal, aggressive, disable). for fiber ports it is combination of global mode and port mode
T/F rlUdldPortDefaultConfiguration	1.3.6.1.4.1.89.218.1.1.4	TruthValue	read-only	This variable indicates whether tne user configure the udld port. to present (default) or not in port configuration.
UDL rlUdldBidirectionalState	1.3.6.1.4.1.89.218.1.1.5	UdldPortBidirectionalState	read-only	This variable identifies the port UDLD status (shutdown, idle, detection, undetermined, bidirectional).
INT rlUdldNumberOfDetectedNeighbors	1.3.6.1.4.1.89.218.1.1.6	INTEGER	read-only	Number Of Detected Neighbors for this port.
rlUdldNeighborTable	1.3.6.1.4.1.89.218.2		not-accessible	The table holds information for Udld Neighbor of ethernet ports.
rlUdldNeighborEntry	1.3.6.1.4.1.89.218.2.1		not-accessible	Entry in the rlUdldNeighborTable.
NUM rlUdldNeighborPortIfIndex	1.3.6.1.4.1.89.218.2.1.1	InterfaceIndex	not-accessible	Interface Index. This variable is the key for udld port Neighbor table. uniquely identifies the udld port index.
STR rlUdldNeighborDeviceID	1.3.6.1.4.1.89.218.2.1.2	UdldString	not-accessible	The Neighbor Device-ID TLV should contain the switch base MAC address in ACSII format.
STR rlUdldNeighborPortID	1.3.6.1.4.1.89.218.2.1.3	UdldString	not-accessible	The Port-ID TLV should contain the port ACSII name as it is printed in show CLI commands.
MAC rlUdldNeighborDeviceMACAddress	1.3.6.1.4.1.89.218.2.1.4	MacAddress	not-accessible	The Neighbor mac address
STR rlUdldNeighborDeviceName	1.3.6.1.4.1.89.218.2.1.5	UdldString	read-only	The Neighbor NeighborDevice Name TLV should contain sysName in ACSII.
INT rlUdldNeighborMessageTime	1.3.6.1.4.1.89.218.2.1.6	INTEGER	read-only	The Neighbor Message Time is from Message Interval TLV. This time interval value used by a neighbor to send UDLD probes after the linkup or detection phases. Its time unit is 1 second.
INT rlUdldNeighborLeftLifeTime	1.3.6.1.4.1.89.218.2.1.7	INTEGER	read-only	The remaining holdtime for Neighbor entry in cache in seconds.
UDL rlUdldNeighborCurrentState	1.3.6.1.4.1.89.218.2.1.8	UdldNeighborCurrentState	read-only	This variable identifies the Neighbor port UDLD current status (Disabled, Enabled, Undefined, Bidirectional).
UDL rlUdldGlobalUDLDMode	1.3.6.1.4.1.89.218.3	UdldGlobalMode	read-write	Define Global UDLD Mode (normal, aggressive, disable)
INT rlUdldGlobalMessageTime	1.3.6.1.4.1.89.218.4	INTEGER	read-write	Define global value of the interval between two sent probe messages, use the udld message time command in Global Configuration mode.

RFC description

Manages Cisco UniDirectional Link Detection (UDLD) protocol on Dell network switches for detecting unidirectional links.

Start monitoring Dell Networking switch (Unidirectional Link Detection) 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 Dell-UDLD-MIB

What Is Dell-UDLD-MIB?

Supported Devices

Monitoring Examples

What Can Be Monitored

This MIB depends on

Related MIBs

RFC description