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Debugging LLDP
You can view the TLVs that your system is sending and receiving.
To view the TLVs, use the following commands.
• View a readable version of the TLVs.
debug lldp brief
• View a readable version of the TLVs plus a hexadecimal version of the entire LLDPDU, including unrecognized TLVs.
debug lldp detail
To stop viewing the LLDP TLVs sent and received by the system, use the no debug lldp command.
Figure 81. The debug lldp detail Command — LLDPDU Packet Dissection
Example of debug lldp Command Output with Unrecognized Reserved and Organizational Specic LLDP TLVs
The following is an example of LLDPDU with both (Reserved and Organizational specic) unrecognized TLVs.
DellEMC#Dec 4 22:38:27 : Received LLDP pkt on TenGigabitEthernet 1/1 of length 204 :
Dec 4 22:38:27 : Packet dump:
Dec 4 22:38:27 : 01 80 c2 00 00 0e 00 a0 c9 00 00 03 81 00 00 00
Dec 4 22:38:27 : 88 cc 02 07 04 00 a0 c9 00 00 01 04 02 05 54 06
Dec 4 22:38:27 : 02 01 2c fe 05 aa bb cc 04 61 fa 01 40 00 00 00
Dec 4 22:38:28 : 00 00 00 00 00 00 00 00 c6 0f ba 27
Dec 4 22:38:28 : TLV: Chassis ID, Len: 7, Subtype: Mac address (4) Value: 00:a0:c9:00:00:01
Dec 4 22:38:29 : TLV: Port ID, Len: 2, Subtype: Interface name (5) Value: T
Dec 4 22:38:29 : TLV: TTL, Len: 2, Value: 300
Dec 4 22:38:29 : TLV: UNKNOWN TLV, ORG_SPEC[aa-bb-cc, 4], Len: 1, Value:a
Dec 4 22:38:29 : aa bb cc 04 61
552
Link Layer Discovery Protocol (LLDP)