Using Cisco Discovery Protocol
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Using Cisco Discovery Protocol

Table Of Contents

Using Cisco Discovery Protocol

Finding Feature Information

Contents

Prerequisites for Using Cisco Discovery Protocol

Restrictions for Using Cisco Discovery Protocol

Information About Using Cisco Discovery Protocol

VLAN Trunking Protocol

Type-Length-Value Fields

Cisco Discovery Protocol

Using Cisco Discovery Protocol with SNMP

Cisco Discovery Protocol and On-Demand Routing Support for ATM PVCs

Cisco Discovery Protocol Support in IPv6

Benefits of Cisco Discovery Protocol

How to Use Cisco Discovery Protocol

Disabling and Enabling Cisco Discovery Protocol on a Supported Device

Disabling Cisco Discovery Protocol on a Supported Device

Enabling Cisco Discovery Protocol on a Supported Device

Disabling and Enabling Cisco Discovery Protocol on a Supported Interface

Disabling Cisco Discovery Protocol on a Supported Interface

Enabling Cisco Discovery Protocol on a Supported Interface

Setting the Transmission Timer and Hold Time

Disabling and Reenabling Cisco Discovery Protocol Version-2 Advertisements

Disabling Cisco Discovery Protocol Version-2 Advertisements

Enabling Cisco Discovery Protocol Version-2 Advertisements

Monitoring and Maintaining Cisco Discovery Protocol

Configuration Examples for Using Cisco Discovery Protocol

Setting the Transmission Timer and Hold Time: Example

Monitoring and Maintaining Cisco Discovery Protocol: Example

Additional References

Related Documents

Standards

MIBs

RFCs

Technical Assistance

Feature Information for Using Cisco Discovery Protocol


Using Cisco Discovery Protocol


First Published: February 1, 1995
Last Updated: October 22, 2009

Cisco Discovery Protocol is a Layer 2 media independent and network independent protocol that runs on Cisco devices and enables networking applications to "learn" about nearby, directly connected devices. This protocol facilitates the management of Cisco devices by discovering these devices, determining how they are configured, and allowing systems using different network-layer protocols to learn about one another.

This module describes Cisco Discovery Protocol and how it functions with Simple Network Management Protocol (SNMP).

Finding Feature Information

For the latest feature information and caveats, see the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the "Feature Information for Using Cisco Discovery Protocol" section.

Use Cisco Feature Navigator to find information about platform support and Cisco IOS XE software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.

Contents

Prerequisites for Using Cisco Discovery Protocol

Restrictions for Using Cisco Discovery Protocol

Information About Using Cisco Discovery Protocol

How to Use Cisco Discovery Protocol

Configuration Examples for Using Cisco Discovery Protocol

Additional References

Feature Information for Using Cisco Discovery Protocol

Prerequisites for Using Cisco Discovery Protocol

Interfaces must support Subnetwork Access Protocol (SNAP) headers.

Restrictions for Using Cisco Discovery Protocol

Cisco Discovery Protocol functions only on Cisco devices.

Cisco Discovery Protocol is not supported on Frame Relay multipoint subinterfaces.

Information About Using Cisco Discovery Protocol

To use Cisco Discovery Protocol, you should understand the following concepts:

VLAN Trunking Protocol

Type-Length-Value Fields

Cisco Discovery Protocol

Benefits of Cisco Discovery Protocol

VLAN Trunking Protocol

VLAN Trunking Protocol (VTP) is a discovery technique that is used by switches. A switch advertises its management domain on its trunk ports, its configuration revision number, and its known VLANs and their specific parameters. A VTP domain is made up of a single device or interconnected devices that share the same VTP domain name. A switch can be in only one VTP domain.

Type-Length-Value Fields

Type-Length-Value (TLV) fields are blocks of information embedded in Cisco Discovery Protocol advertisements. Information in advertisements varies, and the TLV frame format allows for extending advertisements when needed. Table 1 summarizes the TLV definitions.

Table 1 Type-Length-Value Definitions for Cisco Discovery Protocol v2 

TLV
Definition

Device-ID TLV

Identifies the device name in the form of a character string.

Address TLV

Contains the network addresses of both receiving and sending devices.

Port-ID TLV

Identifies the port on which a Cisco Discovery Protocol packet is sent.

Capabilities TLV

Identifies the device type, which indicates the functional capability of the device; for example, a switch.

Version TLV

Contains information about the software release that is running on the device.

Platform TLV

Identifies the hardware platform of the device.

IP Network Prefix TLV

Contains a list of network prefixes to which the sending device can forward IP packets. A prefix includes the interface protocol and port number; for example, Eth 1/0.

VTP Management Domain TLV

Advertises the system's configured VTP management domain name. Used by network operators to verify VTP domain configuration in adjacent network nodes.

Native VLAN TLV

Indicates, per interface, the assumed VLAN for untagged packets on the interface. Cisco Discovery Protocol learns the native VLAN for an interface.

This field is implemented only for interfaces that support the IEEE 802.1Q protocol.

Full/Half Duplex TLV

Indicates the duplex configuration of the Cisco Discovery Protocol broadcast interface. Used by network operators to diagnose connectivity problems between adjacent network devices.


Cisco Discovery Protocol

Cisco Discovery Protocol is a Layer 2 media independent and network independent protocol that networking applications use to learn about nearby, directly connected devices. It is enabled by default. Each device configured for Cisco Discovery Protocol advertises at least one address at which it can receive messages and sends periodic advertisements (messages) to the well-known multicast address 01:00:0C:CC:CC:CC. Devices discover each other by listening at that address. They also listen to messages to learn when interfaces on the other devices are up or go down.

Advertisements contain time-to-live information, which indicates the length of time a receiving device should hold Cisco Discovery Protocol information before discarding it. Advertisements supported and configured in the Cisco IOS XE software are sent by default every 60 seconds on interfaces that support SNAP headers. Cisco devices never forward Cisco Discovery Protocol packets. Each Cisco device that supports Cisco Discovery Protocol stores the information it receives in a table. Information in the table is refreshed each time an advertisement is received, and information about a device is discarded after three advertisements from that device are missed.

The information contained in Cisco Discovery Protocol advertisements varies by the type of device and the version of the operating system running on it. Following is some of the information that Cisco Discovery Protocol can learn:

Cisco IOS XE version running on a Cisco device

Hardware platform of the device

IP addresses of the interfaces on devices

Locally connected devices advertising Cisco Discovery Protocol

Interfaces active on a Cisco device, including encapsulation type

Hostname

Duplex setting

VTP domain

Native VLAN

Cisco Discovery Protocol Version 2 provides more intelligent device tracking features than those available in version 1. One feature is an enhanced reporting mechanism for more rapid error tracking, which helps to reduce network downtime. Errors reported include mismatched native VLAN IDs (IEEE 802.1Q) on connected ports and mismatched port duplex states between connected devices. Messages about reported errors can be sent to the console or to a logging server.

Cisco IOS XE Cisco Discovery Protocol show commands can provide detailed output on VTP management domains and duplex modes of neighboring devices, counters related to Cisco Discovery Protocol, and VLAN IDs of connecting ports.

Using Cisco Discovery Protocol with SNMP

Using Cisco Discovery Protocol with SNMP 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.

The SNMP management application learns protocol addresses and types of neighboring devices by retrieving the Cisco Discovery Protocol tables from SNMP agents in those devices. When enabled, the network management module (NMM) SNMP agent discovers neighboring devices and builds its local cache with information about these devices. A management workstation can retrieve this cache by sending SNMP requests to access the CISCO-CDP-MIB.

Cisco Discovery Protocol and On-Demand Routing Support for ATM PVCs

Cisco Discovery Protocol and On-Demand Routing (ODR) support was added for ATM point-to-point permanent virtual circuits (PVCs). ODR uses Cisco Discovery Protocol to propagate IP address information in hub-and-spoke topologies. When ODR is enabled, spoke routers automatically advertise their subnets using Cisco Discovery Protocol.

Cisco Discovery Protocol is disabled by default on ATM PVC interfaces. To enable Cisco Discovery Protocol, use the cdp run command in global configuration mode and the cdp enable command in interface configuration mode command on both ends of the PVC. To enable ODR, use the router odr command in global configuration mode on the hub router and turn off all dynamic routing protocols in the spoke routers. For details on configuring ODR, see to the "Configuring On-Demand Routing" section of the Cisco IOS XE IP Routing Protocols Configuration Guide, Release 2.

Cisco Discovery Protocol Support in IPv6

Cisco Discovery Protocol in IPv6 functions the same as and offers the same benefits as in IPv4. IPv6 enhancements allow Cisco Discovery Protocol to exchange IPv6 and neighbor addressing information, provide IPv6 information to network management products, and provide troubleshooting tools.

Benefits of Cisco Discovery Protocol

Cisco Discovery Protocol provides the following benefits:

Allows systems using different network-layer protocols to learn about one another

Facilitates managing Cisco devices by discovering them and how they are configured

Assists with troubleshooting TLV fields

Functions with SNMP to learn SNMP agent addresses and to send SNMP queries

How to Use Cisco Discovery Protocol

To configure Cisco Discovery Protocol, perform the following optional tasks:

Disabling and Enabling Cisco Discovery Protocol on a Supported Device

Disabling and Enabling Cisco Discovery Protocol on a Supported Interface

Setting the Transmission Timer and Hold Time

Disabling and Reenabling Cisco Discovery Protocol Version-2 Advertisements

Monitoring and Maintaining Cisco Discovery Protocol

Disabling and Enabling Cisco Discovery Protocol on a Supported Device

Perform the following tasks to disable and enable Cisco Discovery Protocol on a supported device:

Disabling Cisco Discovery Protocol on a Supported Device

Enabling Cisco Discovery Protocol on a Supported Device

Disabling Cisco Discovery Protocol on a Supported Device

Perform this task to disable Cisco Discovery Protocol on a Cisco device.

SUMMARY STEPS

1. enable

2. configure terminal

3. no cdp run

4. end

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

no cdp run

Example:

Router(config)# no cdp run

Disables Cisco Discovery Protocol on a supported device.

Step 4 

end

Example:

Router(config)# end

Returns the command-line interface (CLI) to privileged EXEC mode.

Enabling Cisco Discovery Protocol on a Supported Device

Perform this task to enable Cisco Discovery Protocol on a Cisco device.

SUMMARY STEPS

1. enable

2. configure terminal

3. cdp run

4. end

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

cdp run

Example:

Router(config)# cdp run

Enables Cisco Discovery Protocol on a supported device.

Step 4 

end

Example:

Router(config)# end

Returns the CLI to privileged EXEC mode.

Disabling and Enabling Cisco Discovery Protocol on a Supported Interface

Cisco Discovery Protocol is enabled by default on supported interfaces on a Cisco device. To disable or reenable Cisco Discovery Protocol on an interface, perform these tasks:

Disabling Cisco Discovery Protocol on a Supported Interface

Enabling Cisco Discovery Protocol on a Supported Interface

Disabling Cisco Discovery Protocol on a Supported Interface

Perform this task to disable Cisco Discovery Protocol on a supported interface.


Note If the encapsulation for an interface is changed, it reenables CDP on that interface, even if CDP is previously disabled. For example, when interface encapsulation changes from PPP to HDLC, CDP becomes active even if it is explicitly disabled with the no CDP run command on that interface. This behavior is by design. The encapsulation change, changes the layer 2 protocol configured for that interface and resets the interface configuration to its default CDP state of enabled, assuming CDP is enabled globally on the device.


SUMMARY STEPS

1. enable

2. configure terminal

3. interface type number [name-tag]

4. no cdp enable

5. end

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

interface type number [name-tag]

Example:

Router(config)# interface FastEthernet 0/1

Configures the interface and places the CLI in interface configuration mode.

This example shows how to configure FastEthernet interface 0/1.

Step 4 

no cdp enable

Example:

Router(config-if)# no cdp enable

Disables Cisco Discovery Protocol on an interface.

This example shows how to disable CDP.

Note If the encapsulation for an interface is changed, it reenables CDP on that interface, even if CDP is previously disabled.

Step 5 

end

Example:

Router(config-if)# end

Returns the CLI to privileged EXEC mode.


DETAILED STEPS

Example

If the encapsulation for an interface is changed, it reenables CDP on that interface, even if CDP is previously disabled. For example, when the interface encapsulation changes from PPP to HDLC, CDP become active even if it is explicitly disabled with the no CDP run command on that interface. This behavior is by design. The encapsulation change, changes the layer 2 protocol configured for that interface and resets the interface configuration to its default CDP state of enabled, assuming CDP is enabled globally on the device.

The following examples show that when the encapsulation for an interface is changed, it reenables CDP on that interface, even if CDP is previously disabled:

interface POS3/0
no ip address
encapsulation ppp
shutdown
no cdp enable <<<<<<<<<<CDP Disabled
end

The following example shows that after CDP is disabled, the encapsulation for the interface is changed from PPP to HDLC:

Router#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
Router(config)#int pos3/0
Router(config-if)#encap hdlc    <<<<<<<<<<<<Encapsulation changed from ppp to hdlc.
Router(config-if)#do sh run int pos3/0
Current configuration : 49 bytes
!

The following example shows that CDP is reenabled after the encapsulation for the interface is changed.

interface POS3/0      
no ip address
shutdown        <<<<<<<<<<<<CDP is now back on. You don't see it here previously disabled.
end

Enabling Cisco Discovery Protocol on a Supported Interface

Perform this task to enable Cisco Discovery Protocol on a supported interface.


Note If the encapsulation for an interface is changed, it reenables CDP on that interface, even if CDP is previously disabled.


SUMMARY STEPS

1. enable

2. configure terminal

3. interface type number [name-tag]

4. cdp enable

5. end

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

interface type number [name-tag]

Example:

Router(config)# interface FastEthernet 0/1

Configures the interface and places the CLI in interface configuration mode.

Note If the encapsulation for an interface is changed, it reenables CDP on that interface, even if CDP is previously disabled.

Step 4 

cdp enable

Example:

Router(config-if)# cdp enable

Enables Cisco Discovery Protocol.

Step 5 

end

Example:

Router(config-if)# end

Returns the CLI to privileged EXEC mode.

Setting the Transmission Timer and Hold Time

Perform this task to set the frequency of Cisco Discovery Protocol transmissions and the hold time for Cisco Discovery Protocol packets.

SUMMARY STEPS

1. enable

2. configure terminal

3. cdp timer seconds

4. cdp holdtime seconds

5. end

DETAILED STEPS

 
Command
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

cdp timer seconds

Example:

Router(config)# cdp timer 30

Specifies the frequency of transmission of Cisco Discovery Protocol packets.

In this example, the frequency is set to 30 seconds.

Step 4 

cdp holdtime seconds

Example:

Router(config)# cdp holdtime 90

Specifies the amount of time a receiving device should hold information before discarding it.

In this example, the amount of time is set to 90 seconds.

Step 5 

end

Example:

Router(config)# end

Returns the CLI to privileged EXEC mode.

Disabling and Reenabling Cisco Discovery Protocol Version-2 Advertisements

The broadcasting of Cisco Discovery Protocol Version 2 advertisements is enabled by default on Cisco devices. To disable or reenable this broadcasting, perform these tasks.

Disabling Cisco Discovery Protocol Version-2 Advertisements

Enabling Cisco Discovery Protocol Version-2 Advertisements

Disabling Cisco Discovery Protocol Version-2 Advertisements

Perform this task to disable Cisco Discovery Protocol version-2 advertisements.

SUMMARY STEPS

1. enable

2. configure terminal

3. no cdp advertise-v2

4. end

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

no cdp advertise-v2

Example:

Router(config)# no cdp advertise-v2

Disables the broadcasting of Cisco Discovery Protocol version 2 advertisements.

Step 4 

end

Example:

Router(config)# end

Returns the CLI to privileged EXEC mode.

Enabling Cisco Discovery Protocol Version-2 Advertisements

Perform this task to enable Cisco Discovery Protocol version-2 advertisements.

SUMMARY STEPS

1. enable

2. configure terminal

3. cdp advertise-v2

4. end

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

cdp advertise-v2

Example:

Router(config)# cdp advertise-v2

Enables the broadcasting of Cisco Discovery Protocol version 2 advertisements.

Step 4 

end

Example:

Router(config)# end

Returns the CLI to privileged EXEC mode.

Monitoring and Maintaining Cisco Discovery Protocol

To monitor and maintain Cisco Discovery Protocol on your device, perform the following steps. This task and all steps are optional, and you do not have to perform the steps in the sequence shown.

SUMMARY STEPS

1. enable

2. clear cdp counters

3. clear cdp table

4. show cdp

5. show cdp entry device-name [protocol | version]

6. show cdp interface [type number]

7. show cdp neighbors [type number] [detail]

8. show cdp traffic

9. show debugging

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

clear cdp counters

Example:

Router# clear cdp counters

Resets the traffic counters to zero.

Step 3 

clear cdp table

Example:

Router# clear cdp table

Deletes the Cisco Discovery Protocol table of information about neighbors.

Step 4 

show cdp

Example:

Router# show cdp

Displays the interval between advertisements, the number of seconds the advertisement is valid for a given port, and the version of the advertisement.

Step 5 

show cdp entry device-name [protocol | version]

Example:

Router# show cdp entry device-name protocol

Displays information about a specific neighbor.

Display can be limited to protocol or version information.

Note Enter * for the device name to show all CDP neighbor entries.

Step 6 

show cdp interface [type number]

Example:

Router# show cdp interface

Displays information about interfaces on which Cisco Discovery Protocol is enabled.

Step 7 

show cdp neighbors [type number] [detail]

Example:

Router# show cdp neighbors

Displays the type of device that has been discovered, the name of the device, the number and type of the local interface (port), the number of seconds the Cisco Discovery Protocol advertisement is valid for the interface, the device type, the device product number, and the port ID.

Issuing the detail keyword displays information about the native VLAN ID, the duplex mode, and the VTP domain name associated with neighbor devices.

Step 8 

show cdp traffic

Example:

Router# show cdp traffic

Displays Cisco Discovery Protocol counters, including the number of packets sent and received and checksum errors.

Step 9 

show debugging

Example:

Router# show debugging

Displays information about the types of debugging that are enabled for the router.

Configuration Examples for Using Cisco Discovery Protocol

The following examples show how to set transmission timer and hold time values and show commands you can issue to monitor and maintain Cisco Discovery Protocol.

Setting the Transmission Timer and Hold Time: Example

Monitoring and Maintaining Cisco Discovery Protocol: Example

Setting the Transmission Timer and Hold Time: Example

In the following example, the timer is set to send updates every 30 seconds and a show cdp interface command is issued to show that the update is effective:

router#conf t 
router(config)#cdp timer 30 
router(config)#end 
router# 
router#sh cdp interface gi0/0/0 
GigabitEthernet0/0/0 is up, line protocol is up 
Encapsulation ARPA 
Sending CDP packets every 30 seconds 
Holdtime is 120 seconds 
router# 

In the following example, the hold time is set to 90 seconds and a show cdp interface command is issued to show that the update is effective:

router#conf t  
router(config)#cdp holdtime 90
router(config)#end  
router#  
router#sh cdp interface gi0/0/0  
GigabitEthernet0/0/0 is up, line protocol is up  
Encapsulation ARPA  
Sending CDP packets every 30 seconds  
Holdtime is 90 seconds
router# 

Monitoring and Maintaining Cisco Discovery Protocol: Example

The following example shows a typical series of commands you can issue to view Cisco Discovery Protocol information:

Router# show cdp

Global CDP information:
        Sending CDP packets every 60 seconds
        Sending a holdtime value of 180 seconds
        Sending CDPv2 advertisements is enabled
 
Router# show cdp neighbors

Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge
                  S - Switch, H - Host, I - IGMP, r - Repeater
 
Device ID        Local Intrfce     Holdtme    Capability  Platform  Port ID
C2950-1          Fas 0/0            148         S I       WS-C2950T-Fas 0/15
RX-SWV.cisco.com Fas 0/1            167         T S       WS-C3524-XFas 0/13

Router# show cdp neighbors detail

-------------------------
Device ID: C2950-1
Entry address(es): 
Platform: Cisco WS-C2950T-24,  Capabilities: Switch IGMP 
Interface: FastEthernet0/0,  Port ID (outgoing port): FastEthernet0/15
Holdtime : 139 sec

Version :
Cisco IOS XE C2950 Software (C2950-I6Q4L2-M), Version 12.1(9)EA1, RELEASE SOFTWARE
 .
 .
 .

Router# show cdp traffic

CDP counters :
        Total packets output: 81684, Input: 81790
        Hdr syntax: 0, Chksum error: 0, Encaps failed: 0
        No memory: 0, Invalid packet: 0, Fragmented: 0
        CDP version 1 advertisements output: 0, Input: 0
        CDP version 2 advertisements output: 81684, Input: 81790

Additional References

The following sections provide references related to using Cisco Discovery Protocol.

Related Documents

Related Topic
Document Title

Cisco IOS XE Cisco Discovery Protocol commands

Cisco IOS Network Management Command Reference

Configuring SNMP Support

"Configuring SNMP Support" module

Debugging commands

Cisco IOS Debug Command Reference

Configuring On-Demand Routing

"Configuring On-Demand Routing" module


Standards

Standard
Title

IEEE 802.1Q

Virtual LANS


MIBs

MIB
MIBs Link

CISCO-CDP MIB

To locate and download MIBs for selected platforms, Cisco IOS XE releases, and feature sets, use Cisco MIB Locator found at the following URL:

http://www.cisco.com/go/mibs


RFCs

RFC
Title

No new or modified RFCs are supported, and support for existing RFCs has not been modified.


Technical Assistance

Description
Link

The Cisco Support website provides extensive online resources, including documentation and tools for troubleshooting and resolving technical issues with Cisco products and technologies.

To receive security and technical information about your products, you can subscribe to various services, such as the Product Alert Tool (accessed from Field Notices), the Cisco Technical Services Newsletter, and Really Simple Syndication (RSS) Feeds.

Access to most tools on the Cisco Support website requires a Cisco.com user ID and password.

http://www.cisco.com/techsupport


Feature Information for Using Cisco Discovery Protocol

Table 2 lists the features in this module and provides links to specific configuration information.

Not all commands may be available in your Cisco IOS XE software release. For release information about a specific command, see the command reference documentation.

Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which Cisco IOS XE software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.


Note Table 2 lists only the Cisco IOS XE software release that introduced support for a given feature in a given Cisco IOS XE software release train. Unless noted otherwise, subsequent releases of that Cisco IOS XE software release train also support that feature.


Table 2 Feature Information for Configuring Cisco Discovery Protocol 

Feature Name
Releases
Feature Information

Configuring Cisco Discovery Protocol

Cisco IOS XE Release 2.1

Cisco Discovery Protocol is a Layer 2 media independent and network independent protocol that runs on Cisco devices and enables networking applications to "learn" about nearby, directly connected devices. This protocol facilitates the management of Cisco devices and allows systems using different network-layer protocols to learn about one another.

In Cisco IOS XE Release 2.1, this feature was introduced on Cisco ASR 1000 Series Routers.

The following sections provide information about this feature:

VLAN Trunking Protocol

Type-Length-Value Fields

Cisco Discovery Protocol

Using Cisco Discovery Protocol with SNMP

Cisco Discovery Protocol and On-Demand Routing Support for ATM PVCs

Cisco Discovery Protocol Support in IPv6

Benefits of Cisco Discovery Protocol

How to Use Cisco Discovery Protocol