# VPP Link Layer Discovery Protocol (LLDP) implementation {#lldp_doc} This is a memo intended to contain documentation of the VPP LLDP implementation Everything that is not directly obvious should come here. ## LLDP 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 ### Configuration LLDP has a global configuration and a per-interface enable setting. Global configuration is modified using the "set lldp" command set lldp [system-name <string>] [tx-hold <value>] [tx-interval <value>] 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 <interface> | if_index <idx> [port-desc <string>] [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