What is Cisco Discovery Protocol (CDP)

In this post, we are going to learn what is Cisco CDP protocol 

What is Cisco Discovery Protocol (CDP)

The Cisco discovery protocol (also known as CDP) is a network protocol that operates in layer 2 (Data Link Layer). It is designed by Cisco to gather information about hardware, operating system versions, protocols, and IP address of nearby, directly connected, neighboring Cisco devices. It does all these things in order to simplify network administration of cisco equipment, and as it is designed and developed by Cisco and works on cisco devices only, so it is mainly a Cisco proprietary protocol.

This protocol makes it easier to manage Cisco devices by identifying them, knowing how they're setup, and allowing systems to communicate with each other and learn about one another using various network-layer protocols.

All supported devices, including Cisco routers and switches, have CDP enabled by default.

By default, messages received from a neighboring Cisco device are not transmitted to any other devices. This implies that Cisco Discovery Protocol (CDP) is only sent to Cisco devices that are physically linked. The messages received from neighbor devices are stored in a table that may be seen using the show CDP neighbors command on any Cisco device that implements Cisco Discovery Protocol (CDP).

Whenever a Cisco device, such as a CDP-enabled router, gets a CDP packet, it starts to create a table of adjacent devices. Once the devices have been found, they transmit to each other a packet of updated data on a regular basis. These CDP packets provide a variety of useful data about network devices, including:

  •          Device type
  •          Hardware platform
  •          Hardware capabilities
  •          IOS version number
  •          Hostname
  •          The interface that generates CDP message
  •          IP address of the device
  •          Port ID
  •         Number of seconds for CDP advertisement is valid

the multicast destination address 01:00:0C:CC:CC:CC is used by Cisco devices to deliver Cisco Discovery Protocol (CDP) messages. On interfaces that implement Subnetwork Access Protocol (SNAP) headers, CDP messages are transmitted every 60 seconds. Subnetwork Access Protocol (SNAP) support isn't available on all data link layer media types. Ethernet, Token Ring, Fiber Distributed Data Interface (FDDI), Point-to-Point Protocol (PPP), High-Level Data Link Control (HDLC), Asynchronous Transfer Mode (ATM), and Frame Relay are among the media types supported by Cisco Discovery Protocol (CDP).

Post a Comment

Previous Post Next Post

Ads Unit Top

Ads Botom