Overview of NDSP Protocol

NDSP (Network Devices Searching Protocol) is a device discovery protocol based on multicast packet, which can discover directly connected devices. It organizes  the information of the local device into TLV (type/length/value), which is encapsulated in NDSPPDU (network devices searching protocol data unit) and sent to  the  directly connected neighbor device. At the same time, it also parses the NDSPPDU received from the neighbor device and caches the information of the directly connected device to the local. Through NDSP, the device can save and manage the information of itself and the directly connected neighbor devices for the network management system to query and judge the communication status of the link.

NDSP has only one table – direct connected neighbor table. For general networks, there is only one direct connected neighbor on an interface, so the number of table entries will not exceed the number of interfaces.