Ethernet Link Layer Discovery

Type of course:

Digital learning, Lesson

Language:

Duration:

30 minutes

Workload:

1 hour

Proficiency:

Intermediate

Target:

Professionals, Workers

Imagine plugging a brand‑new switch into an already‑buzzing network and, within seconds, every neighbor knows its name, port ID, and capabilities—no manual spreadsheets, no guesswork. That “handshake” is powered by Link Layer Discovery Protocol (LLDP), the IEEE 802.1AB standard that lets devices advertise exactly who and where they are on a Layer 2 network.

Modern networks are dynamic. Without automatic discovery, documentation lags, troubleshooting stalls, and security gaps appear. LLDP provides the self‑describing fabric that keeps Layer 2 transparent, auditable, and resilient—whether you’re managing a corporate LAN or an industrial PROFINET segment.

Take a moment to visualize your current network: do you know what’s on every port? By the end of this lesson, you’ll not only answer that question—you’ll automate the answer. Let’s dive in and see LLDP at work.

Learning outcomes

Each learner will correctly explain the role of IEEE 802.1AB, list at least five mandatory LLDP TLVs, and contrast LLDP with one proprietary discovery protocol.
Learners will be able to analyze a provided lldpLoc and lldpRem tables and select the correct Layer-2 topology diagram.
Each learner will be able to clarify the purpose of all six primary SNMP PDU types and explain how the manager-agent model functions. Each learner will also be able to describe the workflow how network topology is obtained using SNMP and reading from LLDP MIBs.