The Link Layer Discovery Protocol

LLDP is a vendor-neutral link layer protocol in the Internet Protocol Suite used by network devices for advertising their identity, capabilities, and neighbors on an IEEE 802 local area network, principally wired Ethernet. The protocol is formally referred to by the IEEE as Station and Media Access Control Connectivity Discovery.

LLDP performs functions similar to several proprietary protocols, such as Cisco Discovery Protocol, Foundry Discovery Protocol, Nortel Discovery Protocol and Link Layer Topology Discovery.

Quantellium collects LLDP information by requesting LLDP data from switches (with SNMP) and uses the retrieved information to draw dynamic connection lines between devices.

The figure below shows the information stored in device “ngswitch” that was retrieved using SNMP. Users with at least Operator rights can access this page by opening the dashboard page of a device (right-click a device on the map and select Dashboard from the popup menu) and clicking on the Received LLDP data link .

LLDP data collected through SNMP

How should the above table be read?

The LLDP information is collected from device “ngswitch” through SNMP requests. This device has multiple interfaces to which other equipment is connected.

  • An HP Procurve switch is connected to the local interface g4. Quantellium knows this switch under the name “HP Procurve switch 2524”.
  • An Ubuntu server is connected to the local interface g2. Quantellium knows this server as “Platinum”.

The first two columns are filled with data that Quantellium has collected from various sources. The rest of the columns contain raw data coming directly from device “ngswitch”.