17-2
Cisco IOS Software Configuration Guide for Cisco Aironet Access Points
OL-11350-01
Chapter17 Configuring CDP
Understanding CDP
Understanding CDP
Cisco Discovery Protocol (CDP) is a device-discovery protocol that runs on all Cisco network
equipment. Each device sends identifying messages to a multicast address, and each device monitors the
messages sent by other devices. Information in CDP packets is used in network management software
such as CiscoWorks2000.
CDP is enabled on the access point Ethernet port by default. However, CDP is enabled on the access
point radio port only when the radio is associated to another wireless infrastructure device, such as an
access point or a bridge. CDP is sent on the lowest VLAN number configured on the access point. When
more than on VLAN is used in a wireless network, Cisco recommends that the lowest VLAN number
configured be used as the native VLAN
Note For best performance on your wireless LAN, disable CDP on all radio interfaces and on sub-interfaces
if VLANs are enabled on the access point.
Configuring CDP
This section contains CDP configuration information and procedures:
Default CDP Configuration, page17-2
Configuring the CDP Characteristics, page17-2
Disabling and Enabling CDP, page17-3
Disabling and Enabling CDP on an Interface, page17-4

Default CDP Configuration

Table17-1 lists the default CDP settings.

Configuring the CDP Characteristics

You can configure the CDP holdtime (the number of seconds before the access point discards CDP
packets) and the CDP timer (the number of seconds between each CDP packets the access point sends).
Beginning in Privileged Exec mode, follow these steps to configure the CDP holdtime and CDP timer.
Table17-1 Default CDP Configuration
Feature Default Setting
CDP global state Enabled
CDP interface state Enabled
CDP holdtime (packet holdtime in seconds) 180
CDP timer (packets sent every x seconds) 60