LLDP

Introduction

LLDP or Link-Layer Discovery Protocol is an industry standard protocol designed to supplant proprietary Link-Layer protocols such as EDP or CDP. The goal of LLDP is to provide an inter-vendor compatible mechanism to deliver Link-Layer notifications to adjacent network devices.

help

[lldpcli] # help

-- Help
       show  Show running system information
      watch  Monitor neighbor changes
     update  Update information and send LLDPU on all ports
  configure  Change system settings
unconfigure  Unconfigure system settings
       help  Get help on a possible command
      pause  Pause lldpd operations
     resume  Resume lldpd operations
       exit  Exit interpreter

Usage

At first ensure that the lldpd service is not running, then force it to run in cisco compatible mode, CDP or Cisco Discovery Protocol:

# systemctl stop lldpd

# lldpd -c

then detect the neighbor switch port information connected to your network card:

# lldpcli update

# lldpcli show neighbors
-------------------------------------------------------------------------------
LLDP neighbors:
-------------------------------------------------------------------------------
Interface:    eno1, via: CDPv2, RID: 1, Time: 0 day, 00:00:00
  Chassis:     
    ChassisID:    local SW-2.example.com
    SysName:      SW-2.example.com
    SysDescr:     cisco WS-C2960X-48TS-L running on
                  Cisco IOS Software, C2960X Software (C2960X-UNIVERSALK9-M), Version 15.2(2)E5, RELEASE SOFTWARE (fc2)
                  Technical Support: http://www.cisco.com/techsupport
                  Copyright (c) 1986-2016 by Cisco Systems, Inc.
                  Compiled Thu 02-Jun-16 01:31 by prod_rel_team
    MgmtIP:       192.168.0.3
    Capability:   Bridge, on
    Capability:   Router, on
  Port:        
    PortID:       ifname GigabitEthernet1/0/20
    PortDescr:    GigabitEthernet1/0/20
-------------------------------------------------------------------------------