Link Layer Discovery Protocol (LLDP)

LLDP

The Link Layer Discovery Protocol (LLDP) operates on the data link layer. It stores and maintains information about the local device and the devices directly connected to it for network administrators to manage networks through NMS (network management systems). In LLDP, device information is encapsulated in LLDPDUs in the form of TLV (meaning type, length, and value) triplets and is exchanged between directly connected devices. Information in LLDPDUs received is stored in standard MIB (management information base).

Configuring LLDP

Network Diagram

Figure 1-1 Network diagram for LLDP configuration

Networking and Configuration Requirements

l          As shown in Figure 1-1, connect NMS to Switch A over the Ethernet; and connect Switch A to the MED device and Switch B through GigabitEthernet 1/0/1 and GigabitEthernet 1/0/2 respectively.

l          Configure LLDP on the interfaces of Switch A and Switch B to allow NMS to monitor the link status of Switch A.

Configuration Example

l          Configuration on Switch A

#

interface GigabitEthernet1/0/1

 lldp admin-status rx

#

interface GigabitEthernet1/0/2

 lldp admin-status rx

l          Configuration on Switch B

#

interface GigabitEthernet1/0/1

 lldp admin-status tx

Configuration Guidelines

To display the log information generated by neighbor status changes on the terminal monitor, make sure that the terminal monitor (through the terminal monitor command), log information switch (through the terminal logging command), and information center (through the info-center enable command) are enabled.