Configuring for Network Management Applications

LLDP (Link-Layer Discovery Protocol)

The LLDP “System Descr” field maps to CDP’s “Version” and “Plat- form” fields.

The switch assigns “ChassisType” and “PortType” fields as “local” for both the LLDP and the CDP advertisements it receives.

Both LLDP and CDP support the “System Capability” TLV. However, LLDP differentiates between what a device is capable of supporting and what it is actually supporting, and separates the two types of information into subelements of the System Capability TLV. CDP has only a single field for this data. Thus, when CDP System Capability data is mapped to LLDP, the same value appears in both LLDP System Capability fields.

System Name and Port Descr are not communicated by CDP, and thus are not included in the switch’s Neighbors database.

N o t e

 

Because ProCurve switches do not generate CDP packets, they are not

 

 

represented in the CDP data collected by any neighbor devices running CDP.

 

 

A switch with CDP disabled forwards the CDP packets it receives from other

 

 

devices, but does not store the CDP information from these packets in its own

 

 

MIB.

 

 

 

 

 

 

LLDP data transmission/collection and CDP data collection are both enabled

 

 

 

 

in the switch’s default configuration. In this state, an SNMP network

 

 

management application designed to discover devices running either CDP or

 

 

LLDP can retrieve neighbor information from the switch regardless of whether

 

 

LLDP or CDP is used to collect the device-specific information.

 

 

 

 

 

 

 

 

Protocol State

Packet

Inbound Data Management

Inbound Packet Forwarding

 

 

 

 

Generation

 

 

 

 

 

 

 

 

 

 

 

 

CDP Enabled1

n/a

Store inbound CDP data.

No forwarding of inbound

 

 

 

 

 

 

CDP packets.

CDP Disabled

n/a

No storage of CDP data from

 

 

neighbor devices.

Floods inbound CDP packets from connected devices to outbound ports.

LLDP Enabled1

Generatesand

Store inbound LLDP data.

No forwarding of inbound

 

transmits

 

LLDP packets.

 

LLDP packets

 

 

 

out all ports on

 

 

 

the switch.

 

 

 

 

 

 

LLDP Disabled

No packet

No storage of LLDP data

No forwarding of inbound

 

generation.

from neighbor devices.

LLDP packets.

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