Which management protocol is tightly coupled with YANG?

The management protocol that is tightly coupled with YANG is NETCONF. NETCONF, or Network Configuration Protocol, was designed to provide a standardized way to install, manipulate, and delete the configuration of network devices. One of its main features is its use of XML to encode data and configuration information.

YANG, which stands for Yet Another Next Generation, is a data modeling language used to model configuration and state data for network devices. The synergy between NETCONF and YANG comes from the fact that NETCONF utilizes the YANG data models to define the capabilities and structure of device configurations. When using NETCONF, network administrators can retrieve, modify, and manage configurations based on these YANG models, ensuring that device configurations adhere to defined structures and semantics.

While REST and RESTCONF also deal with network management, RESTCONF specifically is a RESTful API that works with YANG data models through HTTP, facilitating web-based access to the configuration. gRPC, on the other hand, is a modern open-source remote procedure call (RPC) framework that can also interface with YANG, but it's not as tightly integrated as NETCONF is. Thus, NETCONF’s inherent design to work directly with YANG makes it the most closely associated protocol.