Which command enables NETCONF over SSH on IOS XR?

The command that enables NETCONF over SSH on IOS XR is "netconf-yang agent ; ssh." This command establishes the NETCONF environment specifically designed to work with YANG data models, which provides a structured way to manage network devices and services programmatically.

The "netconf-yang agent" portion of the command initiates the NETCONF agent within the IOS XR environment, allowing it to leverage the YANG-based models for configuration and operational data. The inclusion of " ; ssh" signifies that the NETCONF agent will be accessible over the SSH protocol, ensuring secure communication between the management system and the network device.

This approach is essential for modern network automation, as it aligns with industry practices for secure and programmable network management. By using NETCONF over SSH, network operators can automate configurations, retrieve operational data, and ensure that their infrastructure is managed efficiently and securely.