Install guide

2 Software Reference
Introduction
This chapter describes the Link Layer Discovery Protocol (LLDP), how it is
implemented on the switch, and how to configure the switch to use it.
LLDP is a neighbour discovery protocol. Neighbour discovery protocols define
standard methods for Ethernet network devices, such as switches and routers,
to receive and/or transmit device-related information to other nodes on the
network, and to store the information that is learned about other devices.
Link Layer Discovery Protocol
Overview Link Layer Discovery Protocol (LLDP) is a Layer 2 protocol defined by the
IEEE Standard 802.1AB-2005. For a complete set of rules and information about
LLDP, refer to this standard.
LLDP allows Ethernet network devices to advertise details about themselves,
such as device configuration, capabilities and identification, to directly
connected devices on the network that are also using LLDP.
LLDP is a “one hop” protocol; LLDP information can only be sent to and
received by devices that are directly connected to each other by the same link.
Devices that are directly connected to each other are called neighbours.
Advertised information is not forwarded on to other devices on the network.
SNMP LLDP is designed to be managed with Simple Network Management Protocol
(SNMP). We provide a command line interface to manage LLDP, however
SNMP is the recommended interface as LLDP is designed to be automatically
managed from Network Management Systems (NMS).
What LLDP does Advertisements are sent in packets called LLDP Data Units (LLDPDUs). The
data sent and received via LLDPDUs is useful for many reasons. For example,
the switch can discover which of the other devices on the network are each
other’s neighbours, and through which ports they connect to each other.
You can configure the switch to do the following:
■ transmit information about itself to neighbours
■ receive device information from neighbours
■ store and manage received information in an LLDP MIB
Each device that uses LLDP has its own LLDP agent, which is a software entity
that implements LLDP. The LLDP agent is responsible for the reception,
transmission, and management of LLDP.
LLDP defines the following:
■ A set of common advertisement messages (Type Length Values). For more
information, see Type Length Values.
■ A protocol for transmitting and receiving advertisements. For more
information, see Transmission and Reception.
■ A method for storing the information that is contained within received
advertisements. For more information, see Storing LLDP Information.