Introduction to Cisco Discovery Protocol

CDP is short for Cisco Discovery Protocol, a data link layer Protocol. Through this Protocol, our network administrator can obtain information about devices that run the CDP Protocol adjacent to each other.

CDP protocol version:

CDP protocol is divided into two versions: CDPv1 and CDPv2. cisco router 12.0 (3) T or later IOS versions support CDPv2. CDPv1 is enabled by default in IOS 10.3 to 12.0 (3) T versions.

When a cisco device is started, the CDP protocol automatically starts to detect other neighboring devices running the CDP protocol. It is A protocol running on the data link layer, so even if it is running different network layer protocols, such as router A running IP protocol, router B running IPX protocol. You can also obtain device information.

Each device running the CDP protocol regularly sends an announcement message to update the neighbor information. At the same time, each device running CDP also receives CDP messages to record the information of neighboring devices.