Specifications

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Cisco Wireless LAN Controller Configuration Guide

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Chapter 4 Configuring Controller Settings

Configuring the Cisco Discovery Protocol

The Cisco Discovery Protocol (CDP) is a device discovery protocol that runs on all Cisco-manufactured

equipment. A device enabled with CDP sends out periodic interface updates to a multicast address in

order to make itself known to neighboring devices.

The default value for the frequency of periodic transmissions is 60 seconds, and the default advertised

time-to-live value is 180 seconds. The second and latest version of the protocol, CDPv2, introduces new

time-length-values (TLVs) and provides a reporting mechanism that allows for more rapid error tracking,

which reduces downtime.

CDPv1 and CDPv2 are supported on the following devices:

• Cisco 5500, 4400, 2500, and 2100 Series Controllers

Note CDP is not supported on the controllers that are integrated into Cisco switches and routers,

including those inthe Catalyst 3750G Integrated Wireless LAN Controller Switch, the Cisco

WiSM, and the Cisco 28/37/38xx Series Integrated Services Router. However, you can use

the show ap cdp neighbors detail {Cisco_AP | all} command on these controllers in order

to see the list of CDP neighbors for the access points that are connected to the controller.

• CAPWAP-enabled access points

• An access point connected directly to a Cisco 5500, 4400, or 2100 Series Controller

Note To use the Intelligent Power Management feature, ensure that CDPv2 is enabled on the Cisco 2100 and

2500 Series Controllers. CDP v2 is enabled by default.

Note The OEAP 600 access points do not support CDP.

This support enables network management applications to discover Cisco devices.

These TLVs are supported by both the controller and the access point:

• Device-ID TLV: 0x0001—The host name of the controller, the access point, or the CDP neighbor.

• Address TLV: 0x0002—The IP address of the controller, the access point, or the CDP neighbor.

• Port-ID TLV: 0x0003—The name of the interface on which CDP packets are sent out.

• Capabilities TLV: 0x0004—The capabilities of the device. The controller sends out this TLV with a

value of Host: 0x10, and the access point sends out this TLV with a value of Transparent Bridge:

0x02.

• Version TLV: 0x0005—The software version of the controller, the access point, or the CDP

neighbor.

• Platform TLV: 0x0006—The hardware platform of the controller, the access point, or the CDP

neighbor.

• Power Available TLV: 0x001a— The amount of power available to be transmitted by power sourcing

equipment to permit a device to negotiate and select an appropriate power setting.

• Full/Half Duplex TLV: 0x000b—The full- or half-duplex mode of the Ethernet link on which CDP

packets are sent out.

These TLVs are supported only by the access point: