A NetFlow version 9 template record is a record that contains information about the fields that will be present in the data records that follow the template. A template record consists of a template ID, a field count, and a list of field types and lengths. A template record is sent periodically by the NetFlow exporter to the NetFlow collector, so that the collector can parse and interpret the data records correctly. A template record can also be requested by the collector using an options template record. The purpose of a template record is to define the format of data records, which contain the actual information about the IP flows1234.
A. It specifies the data format of NetFlow processes. - This is incorrect, because a template record does not specify the data format of NetFlow processes, but rather the data format of data records. NetFlow processes are the functions that perform flow creation, aggregation, export, and analysis on the NetFlow device or the collector. B. It provides a standardized set of information about an IP flow. - This is incorrect, because a template record does not provide any information about an IP flow, but rather the information about the fields that will be present in the data records. The data records are the ones that provide the information about an IP flow, such as source and destination IP addresses, ports, protocols, bytes, packets, timestamps, and so on. C. It defines the format of data records. - This is correct, because a template record defines the format of data records by specifying the field types and lengths that will be present in the data records. A template record allows the NetFlow collector to parse and interpret the data records correctly, and also enables the NetFlow exporter to use different formats for different types of flows. D. It serves as a unique identification number to distinguish individual data records. - This is incorrect, because a template record does not serve as a unique identification number, but rather as a description of the fields. A template record has a template ID, which is a 16-bit value that identifies the template record uniquely within an export packet, but this ID is not used to distinguish individual data records. The data records are distinguished by their position within the export packet and their association with a template record.
References := 1: NetFlow Version 9 Flow-Record Format [IP Application Services] - Cisco … 2: NetFlow V9 formats - IBM 3: Netflow :: Version 9 - Caligare 4: NetFlow Versions > NetFlow for Cybersecurity | Cisco Press
