Wireless Network Manager Administration Guide

Managing Policies > Policy Hierarchy > Select a Switch Policy > System > Link Layer Discovery Protocol
Table of Contents

Link Layer Discovery Protocol

Link Layer Discovery Protocol (LLDP) is the IEEE 802.1AB standard for Switches to advertise their identity, major capabilities, and neighbors on the 802 LAN. LLDP allows users to views the discovered information to identify system topology and detect faulty configurations on the LAN. LLDP is essentially a neighbor discovery protocol that uses Ethernet connectivity to advertise information to devices on the same LAN and store information about the network. The information transmitted in LLDP advertisements flow in one direction only; from one device to its neighbors. This information allows the device to quickly identify a variety of other devices, resulting in a LAN that interoperates smoothly and efficiently.

LLDP transmits information as packets called LLDP Data Units (LLDPDUs). A single LLDP Protocol Data Unit (LLDP PDU) is transmitted within a single 802.3 Ethernet frame. A basic LLDPDU consists of a set of Type- Length-Value elements (TLV), each of which contains information about the device. A single LLDPDU contains multiple TLVs. TLVs are short information elements that communicate complex data. Each TLV advertises a single type of information.

To activate the Link Layer Discovery Protocol

  1. Navigate to Policies > Policy Hierarchy > Switch Policy.
  2. Select the System tab and scroll down to the Link Layer Discovery Protocol section.
  3. Enable the toggle bar, LLDP Enable.
  4. Specify the Transmit Interval in seconds. the interval at which LLDP advertisement updates are sent. The default value is 30. The range is from 5 to 32767.
  5. Specify the Hold time in seconds. This is the time that LLDP packets are held before packets are discarded and measured in multiples of the Advertised Interval. The default is 4. The range is from 2-10.
  6. Specify the Reinit Delay in seconds. Reinitialization delay is the amount of time of delay before reinitializing LLDP. The default is 2. The range is from 1-10.
  7. Specify the Transmit Delay in seconds. This is the time that passes between successive LLDP frame transmissions. The default is 2 seconds. The range is 1-7 seconds.
  8. Select the Version from the drop-down. The default version is 2.