Which protocol is commonly used for northbound communication in APIC-EM?

In the context of Application Policy Infrastructure Controller - Enterprise Module (APIC-EM), northbound communication typically refers to how the controller interacts with various applications and orchestrators. NETCONF is the most commonly used protocol for northbound communication in APIC-EM because it is specifically designed for network device management and allows for the retrieval and modification of device configurations.

NETCONF operates over SSH, providing a secure channel for communication and enabling APIs that can handle network devices' configurations in a structured way. This protocol brings in capabilities such as transaction management, rollbacks, and data modeling using YANG, making it a robust choice for programmable network environments.

While HTTP is a widely used protocol for web-based communication and could be involved in some API interactions, it does not provide the advanced management features that NETCONF does, which are crucial for programmatically handling network devices. SSH, though secure and often used in network communication, is not specifically designed for northbound API interactions in the way that NETCONF is. TFTP, primarily used for transferring files, lacks the comprehensive features required for configuration and management communications.

Therefore, NETCONF stands out as the appropriate choice for this question related to northbound communication in APIC-EM, leveraging its capabilities to facilitate effective