Lab Objective
Enable LLDP globally on a Cisco switch, verify neighbor discovery works toward both a Cisco and a non-Cisco device, and compare LLDP's output structure against the CDP output examined in the previous lab.
Lab Purpose
CDP, covered in the previous lab, is Cisco-proprietary and only discovers other Cisco devices. LLDP (IEEE 802.1AB) provides equivalent discovery functionality as an open, vendor-neutral standard, making it essential whenever a Cisco switch connects to equipment from another manufacturer.
Lab Topology
Switch1 ---- Gi1/0/1 ---- Switch2 (Cisco)
Switch1 ---- Gi1/0/2 ---- ThirdPartyAP (non-Cisco,
LLDP-only device)Task 1: Enable LLDP Globally
LLDP is disabled by default on Cisco devices, unlike CDP. Enable it globally on Switch1.
Task 2: Verify LLDP Is Running
Confirm LLDP is active and check the configured timers.
Task 3: View LLDP Neighbors
Display the LLDP neighbor summary and confirm both the Cisco switch and the non-Cisco access point appear.
Task 4: View Detailed LLDP Information for the Non-Cisco Device
Display detailed LLDP information specifically for the third-party access point, confirming its system name and management address are discoverable despite not being Cisco equipment.
Solution and Verification
Switch1(config)# lldp runSwitch1# show lldp
Global LLDP Information:
Status: ACTIVE
LLDP advertisements are sent every 30 seconds
LLDP hold time advertised is 120 secondsSwitch1# show lldp neighbors
Device ID Local Intf Hold-time Capability Port ID
Switch2 Gi1/0/1 120 B,R Gi1/0/1
ThirdPartyAP Gi1/0/2 120 W eth0
-- Both a Cisco switch and a non-Cisco access
-- point are discovered -- something CDP alone
-- could never accomplish for the non-Cisco deviceSwitch1# show lldp neighbors detail
Chassis id: aabb.cc00.7788
Port id: eth0
System Name: ThirdPartyAP
Management Addresses:
IP: 192.168.1.80
-- Despite being entirely non-Cisco hardware,
-- its system name and management IP are
-- fully discoverable via LLDPKey Takeaway
LLDP and CDP serve nearly identical purposes and share similar output structure, but LLDP's status as an open IEEE standard makes it the only viable choice for discovering non-Cisco equipment — in a genuinely mixed-vendor environment, both protocols are often run simultaneously, since CDP may still provide slightly richer detail specifically between Cisco devices.