Contains a list of network prefixes to which a sending device can forward IP packets. A prefix contains the interface protocol and port number. For example, Ethernet 1/0. Although CDP is a discovery protocol tool that simplifies the process of updating the inventory of Cisco network devices, it only allows Layer 2 discovery of physical connections. To get a more detailed view of your network topology, including Cisco devices, you should use network monitoring software that includes Layer 3 and Layer 2 discovery. Your network monitoring software should provide a log file and visibility into the availability of all devices on the network, including device status, response time, and downtime. Cisco Discovery Protocol is disabled by default on PVC ATM interfaces. To enable the Cisco Discovery protocol, use the cdp run command in global configuration mode and the cdp enable command in interface configuration mode at both ends of the PVC. To enable ODR, use the router`s ODR command in global configuration mode on the hub router and disable all dynamic routing protocols on the hub-and-spoke routers. For more information about configuring ODR, see the “Configuring On-Demand Routing” section of the IP Routing Configuration Guide: ODR. Most networks have multiple switches and / or routers and to make our lives easier, it is good to have a network card that shows us how everything is connected, what kind of devices we have, which VLAN they belong to and the IP addresses we use. CDP is a Cisco protocol that runs on all Cisco devices and helps us discover Cisco devices on the network.
CDP owns Cisco, runs on the data link layer, and is enabled by default. There is not much difference between the show cdp entry* and show cdp neighbors retail controls. They display essentially the same information. However, the show cdp entry* command has two unique options: display the cdp entry* protocols and display the cdp entry* version. For VMware, ESXi administrators can use the Cisco Discovery protocol to determine which Cisco port is connected to a particular vSwitch. When the log is connected to a vSwitch, administrators can view Cisco switch properties, such as software version and device ID. Cisco Discovery Protocol version 2 transmits native VLAN information between Cisco switches, which was not the case with version 1. If a native VLAN does not match, an error message is displayed on the console. Cisco Discovery Protocol (CDP) is a proprietary Cisco Layer 2 (Data Link Layer) network protocol developed by Cisco to exchange information about other directly connected Cisco devices, such as operating system version and IP address. CDP is a proprietary Layer 2 protocol that is enabled by default on all Cisco devices, including routers and switches, and runs on all LAN and WAN media that support Subnetwork Access Protocol (SNAP). The cdp entry* protocols command only shows you the IP addresses of each directly connected neighbor, while the show cdp entry* version only shows you the IOS version of your directly connected neighbors.
Cisco Discovery performs functions similar to several other proprietary network protocols such as Foundry Discovery Protocol (FDP), Nortel Discovery Protocol (NDP), Link Layer Topology Discovery (LLTD), and vendor-independent Link Layer Discovery Protocol (LLDP). CDP is a very useful protocol for Cisco network engineers. You may not realize how important this protocol is until you feel responsible for a network infrastructure that you know little or nothing about. Cisco Discovery Protocol (CDP) is a proprietary Cisco protocol designed to facilitate network management of Cisco devices by discovering hardware and protocol information on neighboring devices. Using CDP, network engineers can collect information about neighboring network devices, determine the type of hardware or equipment, the version of the software, the active interfaces used by the device (physical or VLAN), how they are configured, and other useful information. That`s a lot of information, and it`s useful for troubleshooting and documenting the network. Although the Cisco Discovery Protocol is a very valuable protocol for network engineers, cybercriminals often exploit it to perform cyberattacks. .
