Which document updated NETCONF in 2011?

The document that updated NETCONF in 2011 is RFC 6241. This document defines the NETCONF protocol, which is used for the network configuration and management of devices. RFC 6241 serves as a specification that builds upon earlier versions and addresses previous limitations, introducing enhancements to improve the protocol's functionality, security, and user experience.

It provides detailed definitions for the operations NETCONF offers, such as retrieving running configurations, committing changes, and managing device state. By establishing these standards, RFC 6241 plays a vital role in ensuring interoperability among different network devices and management applications.

In contrast, RFC 4741 is the original NETCONF protocol specification, while RFC 6020 outlines the data modeling language YANG, which is used in conjunction with NETCONF to define the data structures for configuration and state data. RFC 6200 is not specifically focused on NETCONF, which is why RFC 6241 is the correct answer.