BLADE OS™ Application Guide HP GbE2c Ethernet Blade Switch for c-Class BladeSystem Version 5.1 Advanced Functionality Software

BMD00113, September 2009 127
CHAPTER 7
Link Layer Discovery Protocol
The BLADE OS software support Link Layer Discovery Protocol (LLDP). This chapter discusses
the use and configuration of LLDP on the switch:
 “LLDP Overview” on page 127
 “Enabling or Disabling LLDP” on page 128
 “LLDP Transmit Features” on page 129
 “LLDP Receive Features” on page 133
 “LLDP Example Configuration” on page 135
LLDP Overview
Link Layer Discovery Protocol (LLDP) is an IEEE 802.1AB-2005 standard for discovering and
managing network devices. LLDP uses Layer 2 (the data link layer), and allows network
management applications to extend their awareness of the network by discovering devices that are
direct neighbors of already known devices.
With LLDP, the HP GbE2c Ethernet Blade Switch (GbE2c) can advertise the presence of its ports,
their major capabilities, and their current status to other LLDP stations in the same LAN. LLDP
transmissions occur on ports at regular intervals or whenever there is a relevant change to their
status. The switch can also receive LLDP information advertised from adjacent LLDP-capable
network devices.
In addition to discovery of network resources, and notification of network changes, LLDP can help
administrators quickly recognize a variety of common network configuration problems, such as
unintended VLAN exclusions or mis-matched port aggregation membership.
The LLDP transmit function and receive function can be independently configured on a per-port
basis. The administrator can allow any given port to transmit only, receive only, or both transmit
and receive LLDP information.