NETWORK DISCOVERY
LLDP, Port Descriptions and Network Discovery Playbook
Use neighbour discovery and disciplined port naming to make a live network explain itself.
Why this matters
When a switch port has no description and no neighbour data, troubleshooting starts with tracing cables by hand. LLDP provides vendor-neutral neighbour discovery information such as device identity, port identity and capabilities, subject to device support and configuration.
What LLDP can give you
- Neighbour system name.
- Neighbour port ID.
- Capabilities.
- Management information where advertised.
- Additional TLVs depending on platform and device.
Field use
Compare LLDP neighbour data with your cable schedule. If switch A port 48 says its neighbour is switch B port 47 but the drawing says port 48, you have found a documentation or patching discrepancy before an outage exposes it.
Typical verification
show lldp neighbors
show lldp neighbors detail
Port descriptions are still necessary
LLDP only helps when the neighbour participates. Passive devices, simple cameras, unmanaged switches and some embedded equipment may not advertise useful data. Maintain a human-readable description tied to the permanent cable or endpoint ID.
Good description
description AP-07 | CAB-A024 | Boardroom-East
Poor description
description AP
Client benefit
A self-describing network reduces service time. Technicians can identify what is connected before unplugging anything, compare live topology with documentation, and find accidental patching changes quickly.