Configuring Cdp; About Cdp - Cisco Nexus 9000 Series Configuration Manual

Configuring CDP

This chapter describes how to configure the Cisco Discovery Protocol (CDP) on Cisco NX-OS devices.
This chapter includes the following sections:
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About CDP

The Cisco Discovery Protocol (CDP) is a media-independent and protocol-independent protocol that runs on
all Cisco-manufactured equipment including routers, bridges, access and communication servers, and switches.
You can use CDP to discover and view information about all the Cisco devices that are directly attached to
the device.
CDP gathers protocol addresses of neighboring devices and discovers the platform of those devices. CDP
runs over the data link layer only. Two systems that support different Layer 3 protocols can learn about each
other.
Each device that you configure for CDP sends periodic advertisements to a multicast address. Each device
advertises at least one address at which it can receive SNMP messages. The advertisements also contain
hold-time information, which indicates the length of time that a receiving device should hold CDP information
before removing it. You can configure the advertisement or refresh timer and the hold timer.
CDP Version-2 (CDPv2) allows you to track instances where the native VLAN ID or port duplex states do
not match between connecting devices.
CDP advertises the following type-length-value fields (TLVs):
About CDP, page 23
Licensing Requirements for CDP, page 25
Guidelines and Limitations for CDP, page 25
Default Settings for CDP, page 25
Configuring CDP, page 25
Verifying the CDP Configuration, page 28
Configuration Example for CDP, page 28
Additional References, page 29
Cisco Nexus 9000 Series NX-OS System Management Configuration Guide, Release 6.x
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