Concept Guide

The system processes each LLDP frame to retrieve the type and length, and stores the retrieved data of reserved unrecognized LLDP
TLVs in a list. The stored list of unrecognized TLVs is removed when subsequent LLDP neighbor frame is received, neighbor is lost, or
neighbor ages out. If there are multiple unrecognized TLVs with the same TLV type, only the information of rst unrecognized TLV is stored
and the TLV discard counter is incremented for the successive TLVs.
Organizational Specic Unrecognized LLDP TLVs
The type value for organizational specic TLV is 127.
The system processes each LLDP frame to retrieve the OUI, subtype, and data length, and stores the retrieved data of organizational
specic unrecognized LLDP TLVs in a list. The stored list of organizational TLVs is removed when the neighbor is lost or neighbor ages out.
The software assigns a temporary identication index for each unrecognized organizational specic LLDP TLVs upon receiving more than
one TLV with the same OUI and subtype, but with dierent organizationally dened information strings.
NOTE:
The system increments the TLV discard counter and does not store unrecognized LLDP TLV information in following scenarios:
• If there are multiple TLVs with the same information is received
• If DCBX is down on the receiving interface
The organizational specic TLV list is limited to store 256 entries per neighbor. If TLV entries are more than 256, then the oldest entry (of
that neighbor) in the list is replaced. A syslog message appears when the organization specic unrecognized TLV list exceeds more than
205 entries (80 percent of 256) for you to take action. Following shows the syslog message:
Nov 14 03:01:53 %STKUNIT2-M:CP %LLDP-5-LLDP_ORG_UNRECOGNISED_TLV_MAX: Received Organizational
Specific unrecognised TLVs exceeds threshold (205) from Remote Chassis ID: 4c:76:25:f4:ab:00,
Remote Port ID: fortyGigE 1/2/8/1 on interface: Te 2/31/1
Viewing Unrecognized LLDP TLVs
You can view or retrieve the stored unrecognized (reserved and organizational specic) TLVs using the show lldp neighbor
details command.
View all the LLDP TLV information including unrecognized TLVs, using the snmpwalk and snmpget commands.
Viewing the LLDP Conguration
To view the LLDP conguration, use the following command.
• Display the LLDP conguration.
CONFIGURATION or INTERFACE mode
show config
Examples of Viewing LLDP Congurations
The following example shows viewing an LLDP global conguration.
DellEMC(conf)#protocol lldp
DellEMC(conf-lldp)#show config
!
protocol lldp
advertise dot1-tlv port-protocol-vlan-id port-vlan-id
advertise dot3-tlv max-frame-size
advertise management-tlv system-capabilities system-description
hello 10
566
Link Layer Discovery Protocol (LLDP)