What is the most commonly used protocol for network telemetry?

NetFlow is an industry-standard protocol developed by Cisco that captures metadata about IP traffic flows, including source/destination IP, ports, and protocols, making it a ubiquitous tool for network telemetry, monitoring, and security analysis.

SNMP (Simple Network Management Protocol) is used for managing network devices and collecting operational metrics, but it focuses on device status and performance counters rather than detailed traffic flow information like NetFlow.

TFTP (Trivial File Transfer Protocol) is a simple protocol for transferring files, primarily used for tasks like transferring configuration files to network devices, not for continuous network telemetry.

SMTP (Simple Mail Transfer Protocol) is an application-layer protocol used for sending and receiving email messages, unrelated to network telemetry.