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Difficulty: HardNetwork Performance Monitoring and Metrics

A network administrator is troubleshooting intermittent quality degradation during corporate video conference calls across a site-to-site WAN link. While aggregate interface bandwidth utilization remains below capacity, users report packet arrival time variation (jitter) and video freezing. The administrator needs to analyze flow-level conversation statistics—specifically tracking source/destination IP addresses, port numbers, and byte counts—to pinpoint non-business application traffic consuming link resources. Which telemetry protocol and transport method should be implemented on the WAN edge router to export these flow statistics?

  1. IPFIX exporting flow records over UDP to a network telemetry collectorAnswer
  2. B
    IPFIX exporting flow records over TCP port 514 to guarantee reliable real-time metric delivery
  3. C
    SNMPv2c polling router MIBs using community strings to capture individual layer 4 flow records
  4. D
    Syslog event logging transmitted over UDP port 161 to aggregate active network session metrics

Answer

IPFIX exporting flow records over UDP to a network telemetry collector
IPFIX (IP Flow Information Export) is specifically designed to aggregate and export 5-tuple flow metadata (source IP, destination IP, source port, destination port, protocol) to identify top talkers and bandwidth-consuming applications. Exporting IPFIX flow records over UDP reduces router memory and processing overhead under heavy network traffic.

Step-by-Step Solution

1
Identify the monitoring requirement based on the scenario symptoms.
The scenario requires analyzing flow-level metadata (5-tuple conversation data including source/destination IP, ports, and traffic volume) rather than simple interface-level bandwidth or system event logs.
Interface counters (like those retrieved via standard SNMP polling) show total throughput but cannot differentiate individual application flows causing latency or jitter.
2
Select the appropriate telemetry protocol for flow data export.
IPFIX (IP Flow Information Export) or NetFlow is the industry-standard protocol for generating and exporting flow records.
IPFIX defines template-based record formats containing flow metadata suited for traffic analysis and top-talker identification.
3
Determine the correct transport protocol and configuration.
IPFIX uses UDP to push flow packets to a telemetry collector.
UDP minimizes router CPU overhead and memory state tracking compared to connection-oriented TCP, making it optimal for continuous telemetry streaming.

Key Concept

Flow-Based Telemetry and Metric Collection (IPFIX vs SNMP vs Syslog)
Estimated Time:2m 0s
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Topics

Network Performance Monitoring and Metrics

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