Cisco Discovery Protocol

With the Cisco Discovery Protocol (CDP) page, you can:

Enabled by default, CDP is a device-discovery protocol that the switch uses to gather information about neighboring devices. Information gathered includes device type, links between devices, and the number of ports for each device. Devices discovered using CDP can join a cluster, be displayed on the Cisco Switch Network View map, and be managed by network management applications.

Displaying CDP Neighbors

This table lists the devices with which the switch exchanges CDP messages.

To list and display neighboring devices:

  1. From the CDP Neighbors table, select a device.
  2. Click Browse, Telnet, or Details.
    Click Browse to display through a web-based interface the CDP information currently stored in a neighboring device. The device must support built-in web-based management.
    Click Telnet to log into a neighboring device using Telnet.
    Click Details to display the CDP information currently stored in the switch.

Configuring CDP Options

To set global parameters for CDP:

  1. Verify that CDP is enabled (the Run CDP check box should be checked by default).
    Note: You can disable CDP for the entire switch by deselecting the Run CDP check box; then the enabling of the Individual Port Enable check boxes has no effect.
  2. In the Packet Hold Time field, enter the number of seconds (from 10 to 255) that a neighboring device retains the CDP neighbor information received from this switch.
    If a neighboring device does not receive a CDP message before the hold time expires, the neighboring device drops this switch as a neighbor. The default setting is 180 seconds.
  3. In the Packets Sent Every field, enter the number of seconds (from 5 to 900) between transmissions of CDP messages.
    The default setting is 60 seconds.
  4. Click Apply.

Note: You can see CDP traffic information by clicking Traffic.

Disabling CDP

If you do not want CDP to exchange information with a certain device, you can disable CDP on the port that has the attached device.

To disable CDP on a specific port:

  1. Verify that CDP is enabled (the Run CDP check box should be checked by default).
  2. Deselect the check box next to the port.
  3. Click Apply.

Note: You can disable CDP on the entire switch by deselecting the Run CDP check box and clicking Apply.

Enabling CDP

By default, CDP is enabled on all ports. If you have disabled CDP and want to reenable it on the entire switch:

  1. Select the Run CDP check box to enable it.
  2. Click Apply.