Which protocol is primarily used for extracting data from devices?

The protocol primarily used for extracting data from devices is Simple Network Management Protocol (SNMP). This protocol is designed for network management and monitoring, allowing network administrators to collect and organize information about devices on a network. SNMP works by querying devices, such as routers, switches, and servers, to retrieve performance metrics, device configuration, and operational status. It operates using a "manager-agent" model where the manager sends requests to the agents on the devices and receives responses containing the requested data.

While NETCONF and RESTCONF are also used to interact with network devices, they primarily focus on configuration management rather than simple data extraction. NETCONF uses XML-based messages over SSH to manage and configure devices, and RESTCONF is a RESTful API modeled on the architecture of REST principles, allowing access to data in a device via HTTP. On the other hand, XML is a markup language that can be used for representation in data exchange but is not a protocol itself. Thus, when it comes to specifically extracting and gathering data from network devices, SNMP is the most relevant and effective choice.