Cisco Catalyst 4500 Series - Chapter 28 Configuring CDP

28-2
Software Configuration Guide—Release IOS XE 3.3.0SG and IOS 15.1(1)SG
OL-25340-01
Chapter 28 Configuring CDP
Configuring CDP
CDP runs on all LAN and WAN media that support Subnetwork Access Protocol (SNAP).
Each CDP-configured device sends periodic messages to a multicast address. Each device advertises at
least one address at which it can receive SNMP messages. The advertisements also contain the
time-to-live, or holdtime information, which indicates the length of time a receiving device should hold
CDP information before discarding it.
Configuring CDP
The following sections describe how to configure CDP:
• Enabling CDP Globally, page 28-2
• Displaying the CDP Global Configuration, page 28-2
• Enabling CDP on an Interface, page 28-3
• Displaying the CDP Interface Configuration, page 28-3
• Monitoring and Maintaining CDP, page 28-3
Enabling CDP Globally
To enable CDP globally, use this command:
This example shows how to enable CDP globally:
Switch(config)# cdp run
Displaying the CDP Global Configuration
To display the CDP configuration, use this command:
This example shows how to display the CDP configuration:
Switch# show cdp
Global CDP information:
Sending CDP packets every 120 seconds
Sending a holdtime value of 180 seconds
Sending CDPv2 advertisements is enabled
Switch#
For additional CDP show commands, see the “Monitoring and Maintaining CDP” section on page 28-3.
Command Purpose
Switch(config)# [no] cdp run
Enables CDP globally.
Use the no keyword to disable CDP globally.
Command Purpose
Switch# show cdp
Displays global CDP information.