Lldp Configuration; Background; Basic Concepts - HP V1910 Switch Series User Manual

LLDP configuration

Background

In a heterogeneous network, it is important that different types of network devices from different vendors
can discover one other and exchange configuration for interoperability and management sake. A
standard configuration exchange platform was created.
The IETF drafted the Link Layer Discovery Protocol (LLDP) in IEEE 802.1AB. The protocol operates on the
data link layer to exchange device information between directly connected devices. With LLDP, a device
sends local device information as TLV (type, length, and value) triplets in LLDP Data Units (LLDPDUs) to the
directly connected devices, and at the same time, stores the device information received in LLDPDUs sent
from the LLDP neighbors in a standard management information base (MIB). It allows a network
management system to quickly detect and identify Layer 2 network topology changes.

Basic concepts

LLDPDUs
LLDP sends device information in LLDPDUs. LLDPDUs are encapsulated in Ethernet II or Subnetwork
Access Protocol (SNAP) frames.
Ethernet II-encapsulated LLDPDU format
1.
Figure 183 Ethernet II-encapsulated LLDPDU format
Table 88 Fields in an Ethernet II encapsulated LLDPDU
Field
Destination MAC address
Source MAC address
Type
Data
Description
The MAC address to which the LLDPDU is advertised. It is fixed to
0x0180-C200-000E, a multicast MAC address.
The MAC address of the sending port. If the port does not have a MAC
address, the MAC address of the sending bridge is used.
The Ethernet type for the upper layer protocol. It is 0x88CC for LLDP.
LLDPDU.
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