Cisco Discovery Protocol (CDP) and View of Neighboring Devices on SA540 Security Appliance


Fri, 07/08/2016 - 16:50
Apr 26th, 2016
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Article ID: 1010


Cisco Discovery Protocol (CDP) is applied to all equipment that is manufactured by Cisco. Any device with CDP should be able to send messages to multicast address and listen to messages sent by other neighbor devices which help determine the status of the other device.

This document explains how to configure Cisco Discovery Protocol (CDP) and how to view the list of CDP neighbors connected to the device on SA540 Security Appliance.

Note: It is not recommended to enable CDP on the Dedicated WAN port and the Optional ports because they are connected to unsecure networks.

Applicable Devices

• SA540 Security Appliance

Software Version


Configure Cisco Discovery Protocol (CDP)

Step 1. Log in to the Security Appliance configuration utility page and choose Network Management > CDP. The CDP Page opens:


Step 2. From the CDP drop-down list, choose one of the following options:

• Enable All — Enable CDP on all ports supported by the Device.

• Disable All — Disable CDP on all ports supported by the Device.

• Per Port — Configure CDP on selective ports, displayed in the port information table.

Step 3. Enter the CDP Timer in the CDP timer field. This is the time interval in seconds between a successive CDP packet sent by the router.

Step 4. In the CDP Hold Timer field, enter the CDP Hold Timer. This is the amount of time in seconds needed for the information sent in the CDP packet to be caught by the device that receives the CDP packet. Information held longer than the CDP hold timer will expire.

Step 5. In the Enable CDP area, check the interfaces which you would like CDP be enabled on. 

Note: Step 5 is available only when the per port option is chosen in Step 2. 

Step 6. Click Apply to save your settings.

View the List of CDP Neighbors Connected to the Device

Step 1. Log in to the Security Appliance configuration utility page and choose Status > CDP Neighbor. The CDP Neighbor page opens:


The CDP Neighbor List table displays the following information:

• Device ID — Displays the device ID of the neighboring device.

• Local Port — Displays the interface on which the neighbor was discovered.

• Duration — Displays the number of minutes a device has been connected.

• Function — Displays the type of device connected.

– R — Router

– T — Switch Bridge

– S — Switch

– H — Host

– I — Internet Group Management Protocol

– r — Repeater

• Platform — Displays the Cisco platform identifier or the unique device ID of the neighboring device.

• Interface ID — Displays the interface ID of the neighboring device.



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