LLDP Protocol

This is a memo intended to contain documentation of the VPP LLDP (Link Layer Discovery Protocol) implementation Everything that is not directly obvious should come here.


LLDP is a link layer protocol to advertise the capabilities and current status of the system.

There are 2 nodes handling LLDP

1.) input-node which processes incoming packets and updates the local database 2.) process-node which is responsible for sending out LLDP packets from VPP side


LLDP has a global configuration and a per-interface enable setting.

Global configuration is modified using the “set lldp” command

set lldp [system-name ] [tx-hold ] [tx-interval ]

system-name: the name of the VPP system sent to peers in the system-name TLV tx-hold: multiplier for tx-interval when setting time-to-live (TTL) value in the LLDP packets (TTL = tx-hold * tx-interval + 1, if TTL > 65535, then TTL = 65535) tx-interval: time interval between sending out LLDP packets

Per interface setting is done using the “set interface lldp” command

set interface lldp | if_index [port-desc ] [disable]

interface: the name of the interface for which to enable/disable LLDP if_index: sw interface index can be used if interface name is not used. port-desc: port description disable: LLDP feature can be enabled or disabled per interface.

Configuration example

Configure system-name as “VPP” and transmit interval to 10 seconds:

set lldp system-name VPP tx-interval 10

Enable LLDP on interface TenGigabitEthernet5/0/1 with port description

set interface lldp TenGigabitEthernet5/0/1 port-desc vtf:eth0

Operational data

The list of LLDP-enabled interfaces which are up can be shown using “show lldp” command

Example: DBGvpp# show lldp Local interface Peer chassis ID Remote port ID Last heard Last sent Status GigabitEthernet2/0/1 never 27.0s ago inactive TenGigabitEthernet5/0/1 8c:60:4f:dd:ca:52 Eth1/3/3 20.1s ago 18.3s ago active

All LLDP configuration data with all LLDP-enabled interfaces can be shown using “show lldp detail” command

Example: DBGvpp# show lldp detail LLDP configuration: Configured system name: vpp Configured tx-hold: 4 Configured tx-interval: 30

LLDP-enabled interface table:

Interface name: GigabitEthernet2/0/1 Interface/peer state: inactive(timeout) Last known peer chassis ID: Last known peer port ID: Last packet sent: 12.4s ago Last packet received: never

Interface name: GigabitEthernet2/0/2 Interface/peer state: interface down Last packet sent: never

Interface name: TenGigabitEthernet5/0/1 Interface/peer state: active Peer chassis ID: 8c:60:4f:dd:ca:52(MAC address) Remote port ID: Eth1/3/3(Locally assigned) Last packet sent: 3.6s ago Last packet received: 5.5s ago