C H A P T E R
6
Implementing CDP
Cisco Discovery Protocol
(CDP) is a media- and protocol-independent protocol that runs on all
Cisco-manufactured equipment including routers, bridges, access and communication servers, and switches.
Using CDP, you can view information about all the Cisco devices that are directly attached to the device.
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Prerequisites for Implementing CDP, page 57
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Information About Implementing CDP, page 57
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How to Implement CDP on Cisco IOS XR Software, page 59
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Configuration Examples for Implementing CDP, page 63
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Additional References, page 64
Prerequisites for Implementing CDP
You must be in a user group associated with a task group that includes the proper task IDs. The command
reference guides include the task IDs required for each command. If you suspect user group assignment is
preventing you from using a command, contact your AAA administrator for assistance.
Information About Implementing CDP
CDP is primarily used to obtain protocol addresses of neighboring devices and discover the platform of those
devices. CDP can also be used to display information about the interfaces your router uses. CDP is media-
and protocol-independent, and runs on all equipment manufactured by Cisco, including routers, bridges, access
servers, and switches.
Use of SNMP with the CDP MIB allows network management applications to learn the device type and the
SNMP agent address of neighboring devices and to send SNMP queries to those devices. CDP uses the
CISCO-CDP-MIB.
CDP runs on all media that support Subnetwork Access Protocol (SNAP), including LAN, Frame Relay, and
ATM physical media. CDP runs over the data link layer only. Therefore, two systems that support different
network-layer protocols can learn about each other.
Each device configured for CDP sends periodic messages, known as
advertisements
, to a multicast address.
Each device advertises at least one address at which it can receive SNMP messages. The advertisements also
System Management Configuration Guide for Cisco NCS 5000 Series Routers, IOS XR Release 6.2.x
57