Nortel Networks 2500 Series manual Lldp operational modes, Connectivity and management information

Switch management features 75

Figure 22

How LLDP works

1.The Ethernet Routing Switch and router advertise chassis or port IDs and system descriptions to each other.

2.The devices store the information about each other in local MIB databases, accessible using SNMP.

3.A network management system retrieves the data stored by each device and builds a network topology map.

LLDP operational modes

LLDP is a one-way protocol. An LLDP agent can transmit information about the capabilities and current status of the system associated with its MAC service access point (MSAP) identifier. The LLDP agent can also receive information about the capabilities and current status of the system associated with a remote MSAP identifier. However, LLDP agents cannot solicit information from each other.

You can set the local LLDP agent to transmit only, receive only, or to both transmit and receive LLDP information. You can configure the state for LLDP reception and transmission using SNMP or CLI commands.

Connectivity and management information

The information fields in each LLDP frame are contained in a Link Layer Discovery Protocol Data Unit (LLDPDU) as a sequence of short, variable length, information elements known as type, length, value (TLV). Each LLDPDU includes the following four mandatory TLVs:

•chassis ID TLV

Nortel Ethernet Routing Switch 2500 Series

Overview — System Configuration

NN47215-500 (323162-B) 02.02 Standard

4.1 19 November 2007

Copyright © 2007, Nortel Networks