- Preface
- 1 - Overview of Access Point Features
- 2 - Using the Web-Browser Interface
- 3 - Using the Command-Line Interface
- 4 - Configuring the Access Point for the First Time
- 5 - Administrating the Access Point
- 6 - Configuring Radio Settings
- 7 - Configuring Multiple SSIDs
- 8 - Configuring Spanning Tree Protocol
- 9 - Configuring an Access Point as a Local Authenticator
- 10 - Configuring WLAN Authentication and Encryption
- 11 - Configuring Authentication Types
- 12 - Configuring Other Services
- 13 - Configuring RADIUS and TACACS+ Servers
- 14 - Configuring VLANs
- 15 - Configuring QoS
- 16 - Configuring Filters
- 17 - Configuring CDP
- 18 - Configuring SNMP
- 19 - Configuring Repeater and Standby Access Points and Workgroup Bridge Mode
- 20 - Managing Firmware and Configurations
- 21 - Configuring L2TPv3 Over UDP/IP
- 22 - Configuring Ethernet over GRE
- 23 - Configuring System Message Logging
- 24 - Troubleshooting
- 25 - Miscellaneous AP-Specific Configurations
- Appendix A - Protocol Filters
- Appendix B - Supported MIBs
- Appendix C - Error and Event Messages
Configuring CDP
This chapter describes how to configure Cisco Discovery Protocol (CDP) on your access point.
Note For complete syntax and usage information for the commands used in this chapter, refer to the Cisco Aironet IOS Command Reference for Access Points and Bridges for this release and the Cisco IOS Configuration Fundamentals Command Reference for Release 12.2.
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 Cisco Prime Infrastructure2000.
CDP is used in network management to know about the neighbors of a given network device. 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, We recommend 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
- Configuring the CDP Characteristics
- Disabling and Enabling CDP
- Disabling and Enabling CDP on an Interface
Default CDP Configuration
Table 17-1 lists the default CDP settings.
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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.
Use the no form of the CDP commands to return to the default settings.
This example shows how to configure and verify CDP characteristics:
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show cdpGlobal CDP information:
Sending a holdtime value of 120 seconds
Sending CDP packets every 50 seconds
For additional CDP show commands, see the “Monitoring and Maintaining CDP” section.
Disabling and Enabling CDP
CDP is enabled by default. Beginning in Privileged Exec mode, follow these steps to disable the CDP device discovery capability.
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Beginning in privileged EXEC mode, follow these steps to enable CDP:
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This example shows how to enable CDP.
Disabling and Enabling CDP on an Interface
CDP is enabled by default on all supported interfaces to send and receive CDP information.
Beginning in privileged EXEC mode, follow these steps to disable CDP on an interface:
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Enter interface configuration mode, and enter the interface on which you are disabling CDP. |
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Beginning in privileged EXEC mode, follow these steps to enable CDP on an interface:
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Enter interface configuration mode, and enter the interface on which you are enabling CDP. |
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This example shows how to enable CDP on an interface.
Monitoring and Maintaining CDP
To monitor and maintain CDP on your device, perform one or more of these tasks, beginning in privileged EXEC mode.
Below are six examples of output from the CDP show privileged EXEC commands:
Global CDP information:
Sending CDP packets every 50 seconds
Sending a holdtime value of 120 seconds
Enabling CDP Logging
You can enable CDP logging. To log errors related to duplex-mismatches identified through CDP, use the global configuration command cdp log mismatch duplex. To log errors related to duplex mismatches reported through CDP on a particular interface, use the same command at the interface level.
The following example enables logging for errors related to duplex-mismatches identified through CDP on the gigabit Ethernet interface, but disables logging for errors related to duplex-mismatches identified through CDP on the Radio 0 interface.