What is a feature of NetFlow Secure Event Logging?

NetFlow Secure Event Logging (NSEL) is a security logging mechanism that is built on NetFlow Version 9 technology. It provides a stateful, IP flow tracking method that exports only those records that indicate significant events in a flow, such as flow-create, flow-teardown, and flow-denied. NSEL events are triggered by the event that caused the state change in the flow. This reduces the amount of data that is exported and provides more relevant information for security analysis. NSEL also supports periodic flow-update events, which provide byte counters over the duration of the flow. These events are usually time-driven, but may also be triggered by state changes in the flow. NSEL uses templates to describe the format of the data records that are exported through NetFlow. Each event has several record formats or templates associated with it. NSEL delivers templates and data records to configured NSEL collectors through NetFlow over UDP only. NSEL also allows filtering of NSEL events based on the traffic and event type through Modular Policy Framework, and then sends records to different collectors. The supported event types are flow-create, flow-denied, flow-teardown, flow-update, and all. References :=

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NetFlow Secure Event Logging (NSEL) - Cisco

NetFlow Secure Event Logging (NSEL) - Cisco

Implementing and Operating Cisco Security Core Technologies (SCOR) v1.0 (source book)