How to Use the Command 'vnstati' (with Examples)

The vnstati command is a valuable tool for generating visual statistics of network traffic using vnStat data. It outputs network statistics as PNG images, allowing for easy sharing and interpretation of data usage over specific periods. This tool is especially useful for network administrators and IT professionals who want to visually track network usage trends, monitor network performance, and present data to management or clients.

Use Case 1: Output a Summary of the Last 2 Months, Days, and All-Time

Code:

vnstati --summary --iface network_interface --output path/to/output.png

Motivation:

Generating a summary of network traffic over the last two months, days, and all-time helps in understanding the broader trends in network use. This information can help IT administrators identify peak usage periods, evaluate the performance of network resources, and plan for future needs based on historical data.

Explanation:

• --summary: This flag tells vnstati to create a comprehensive summary image. It includes various time frames such as the last two months, days, and all-time traffic statistics.
• --iface network_interface: This argument specifies the network interface for which the statistics will be generated. You need to replace network_interface with the actual interface you wish to monitor (e.g., eth0, wlan0).
• --output path/to/output.png: This specifies the file path where the generated PNG image will be saved. You need to replace path/to/output.png with the actual path and file name where you want to store the output.

Example Output:

The output will be a single PNG image containing a summary of the network’s data usage, breaking down traffic into the last two months, individual days, and the total over time. This visualization typically includes data points like total bytes transferred, average traffic, and more.

Use Case 2: Output the 10 Most Traffic-Intensive Days of All Time

Code:

vnstati --top 10 --iface network_interface --output path/to/output.png

Motivation:

Identifying the top 10 days with the highest traffic is crucial for understanding when the network experiences heavy utilization. This can help in pinpointing potential issues, justifying the need for bandwidth upgrades, and forecasting future capacity requirements.

Explanation:

• --top 10: This option extracts and presents the data for the 10 days with the highest network traffic over the entire period vnStat has been recording.
• --iface network_interface: Specify the particular network interface to examine. As with all use cases, replace network_interface with the actual interface identifier.
• --output path/to/output.png: Designate where the output image should be saved on your system, ensuring you modify path/to/output.png to your desired location.

Example Output:

The outcome is a PNG image showcasing a detailed view of the 10 most traffic-intensive days, ranked and tabulated by traffic volume. It provides insight into extreme usage scenarios and helps identify patterns or deeper analysis needs.

Use Case 3: Output Monthly Traffic Statistics from the Last 12 Months

Code:

vnstati --months --iface network_interface --output path/to/output.png

Motivation:

Monthly traffic statistics give a clear picture of growth or changes in network usage over the past year. Such information is essential for assessing seasonal trends or validating the impact of new applications, policies, or events on the network.

Explanation:

• --months: This flag instructs vnstati to compile monthly statistics for the last 12 months, providing a longitudinal view of data usage.
• --iface network_interface: Indicates the relevant network interface for the statistics. Replace network_interface with the correct interface name.
• --output path/to/output.png: Defines the path where the resulting image will be saved. You must adjust path/to/output.png to fit your file structure and naming conventions.

Example Output:

A PNG file will be produced, illustrating a breakdown of monthly bandwidth usage for the past 12 months. This visualization highlights fluctuations in network traffic, assisting in resource allocation and planning.

Use Case 4: Output Hourly Traffic Statistics from the Last 24 Hours

Code:

vnstati --hours --iface network_interface --output path/to/output.png

Motivation:

Examining hourly traffic statistics for the last 24 hours allows network administrators to catch real-time issues such as unexpected traffic spikes, potential security breaches, or unusual network behavior.

Explanation:

• --hours: This command flag requests hourly statistics for the last 24 hours to be visualized.
• --iface network_interface: As with other cases, this defines which interface’s statistics will be captured. Replace network_interface with the desired interface.
• --output path/to/output.png: Specifies the destination for the output image. You will need to tailor path/to/output.png to your particular needs.

Example Output:

The generated image will detail each hour’s data usage in the last 24 hours, allowing for an immediate overview of hourly network activity. This helps quickly identify any windows of abnormal or excessive network behavior.

Conclusion

The vnstati command provides a versatile set of options for generating PNG images of network statistics data, enhancing the visibility into network utilization. By using the detailed flag options, network administrators and IT professionals can tailor these outputs to their monitoring and reporting needs, ensuring clarity and actionable insight from network usage data.