Release Notes (available on the HPE Networking website). If LLDP has not yet been implemented (or if you are
running an older version of software), consult a previous version of the Management and Configuration Guide for
device discovery details.
LLDP (Link Layer Discovery Protocol): provides a standards-based method for enabling the switches covered
in this guide to advertise themselves to adjacent devices and to learn about adjacent LLDP devices.
LLDP-MED (LLDP Media Endpoint Discovery): Provides an extension to LLDP and is designed to support VoIP
deployments.
NOTE: LLDP-MED is an extension for LLDP, and the switch requires that LLDP be enabled as a
prerequisite to LLDP-MED operation.
An SNMP utility can progressively discover LLDP devices in a network by:
Procedure
1. Reading a given device's Neighbors table (in the Management Information Base, or MIB) to learn about other,
neighboring LLDP devices.
2. Using the information learned in step 1 to find and read the neighbor devices' Neighbors tables to learn about
additional devices, and so on.
Also, by using show commands to access the switch's neighbor database for information collected by an
individual switch, system administrators can learn about other devices connected to the switch, including device
type (capability) and some configuration information. In VoIP deployments using LLDP-MED on the switches,
additional support unique to VoIP applications is also available. See
LLDP-MED (media-endpoint-discovery) on
page 187.
General LLDP operation
An LLDP packet contains data about the transmitting switch and port. The switch advertises itself to adjacent
(neighbor) devices by transmitting LLDP data packets out all ports on which outbound LLDP is enabled and by
reading LLDP advertisements from neighbor devices on ports that are inbound LLDP-enabled. (LLDP is a one-
way protocol and does not include any acknowledgement mechanism.) An LLDP-enabled port receiving LLDP
packets inbound from neighbor devices stores the packet data in a Neighbor database (MIB).
LLDP-MED
This capability is an extension to LLDP and is available on the switches. See LLDP-MED (media-endpoint-
discovery) on page 187.
Packet boundaries in a network topology
• Where multiple LLDP devices are directly connected, an outbound LLDP packet travels only to the next LLDP
device. An LLDP-capable device does not forward LLDP packets to any other devices, regardless of whether
they are LLDP-enabled.
• An intervening hub or repeater forwards the LLDP packets it receives in the same manner as any other
multicast packets it receives. Thus, two LLDP switches joined by a hub or repeater handle LLDP traffic in the
same way that they would if directly connected.
• Any intervening 802.1D device or Layer-3 device that is either LLDP-unaware or has disabled LLDP operation
drops the packet.
172 Aruba 2530 Management and Configuration Guide for
ArubaOS-Switch 16.05
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