How to Check Cloud Server Bandwidth: A Step-by-Step Guide

Knowing how to check cloud server bandwidth is essential for system administrators, DevOps engineers, and VPS users to ensure optimal network performance, identify bottlenecks, and control infrastructure costs. In this guide, Viettel IDC explains several effective methods for measuring and monitoring cloud server bandwidth using popular tools and cloud management platforms.

How to Check Cloud Server Bandwidth Using iPerf

iPerf3 is one of the most widely used network performance testing tools. It operates on a client-server model and allows users to measure the maximum bandwidth achievable between two machines by generating traffic and analyzing actual transfer speeds.

Step 1: Install iPerf3 on Ubuntu/Debian

On Ubuntu and Debian systems, iPerf3 is available through the default package repository. Install it using the following command:

sudo apt update && sudo apt install iperf3 -y

Step 2: Start iPerf3 in Server Mode

iPerf3 requires at least two systems (or two terminal sessions): one acting as the server and the other as the client.

On the server machine, start iPerf3 in server mode:

iperf3 -s

After execution, iPerf3 will display a message indicating that it is listening for incoming connections.

On the client machine, run the following command to test bandwidth toward the server:

iperf3 -c <server_ip_address>

Replace <server_ip_address> with the IP address or hostname of the server.

By default, iPerf3 performs a 10-second upload test from the client to the server.

To test the reverse direction (download speed from the server to the client), use the -R option:

iperf3 -c <server_ip_address> -R

The -R parameter reverses the traffic flow, allowing the server to send data and measure download bandwidth from the client's perspective.

Step 3: Advanced Testing Options

iPerf3 provides several options for customizing network performance tests:

- -t 30 — Run the test for 30 seconds instead of the default 10 seconds.

- -P 4 — Use four parallel TCP streams to maximize bandwidth utilization.

- -u — Perform a UDP bandwidth test (requires specifying bandwidth using the -b option).

Step 4: Analyze the Results

When the test completes, iPerf3 displays detailed results on both the client and server.

Key metrics include:

- Bandwidth: Actual network throughput (Mbps or Gbps).

- Retr: Number of retransmitted packets (lower values indicate better network quality).

- Jitter: Variation in packet delay (for UDP tests).

- Lost/Total Datagrams: Number of lost packets during UDP transmission.

Measuring Cloud Server Bandwidth with Speedtest

Speedtest CLI is the official command-line version of Ookla's Speedtest service. It allows users to measure internet connectivity directly from the terminal without using a web browser.

Step 1: Install the Official Ookla Speedtest CLI

First, ensure the Speedtest CLI package is installed according to your operating system.

Once installed, you can begin testing internet bandwidth from your cloud server.

Step 2: Run a Speed Test

Execute the following command:

speedtest

The tool automatically selects the nearest Speedtest server based on latency and performs upload and download tests.

When running Speedtest for the first time, type YES to accept the license agreement.

Step 3: Select a Specific Test Server

To choose a particular Speedtest server:

List available servers:

speedtest -L

Run a test against a specific server:

speedtest -s <server_id>

Replace <server_id> with the desired server identifier.

Step 4: Export Test Results

Speedtest supports exporting results for reporting and analysis.

Generate output in CSV format:

speedtest --format=csv

Generate output in JSON format:

speedtest --format=json

Create a shareable result URL:

speedtest --share

Step 5: Interpret the Results

The output typically includes:

- Ping – Network latency in milliseconds (lower is better).

- Download Speed – Download bandwidth (Mbps).

- Upload Speed – Upload bandwidth (Mbps).

- Result URL – A shareable link for reporting or troubleshooting.

How to Monitor Cloud Server Bandwidth with Nload

Unlike iPerf3 and Speedtest, which actively generate test traffic, Nload is a real-time bandwidth monitoring tool that displays live network traffic on server interfaces.

Step 1: Install Nload

Ubuntu/Debian

sudo apt install nload

CentOS/RHEL

Enable the EPEL repository first:

sudo yum install epel-release

sudo yum install nload

Fedora and Arch Linux

Nload can also be installed using dnf or pacman.

Most modern Linux distributions include Nload in their official repositories.

Step 2: Launch Nload

Monitor all network interfaces:

nload

Monitor a specific interface:

nload eth0

Once launched, Nload begins displaying live traffic statistics and graphical bandwidth charts.

Step 3: Understand the Metrics

Nload displays two primary graphs:

- Incoming – Data received by the server.

- Outgoing – Data transmitted from the server.

Important statistics include:

- Curr – Current transfer rate.

- Avg – Average transfer rate.

- Max – Highest recorded transfer rate.

- Ttl – Total traffic transferred during the session.

If multiple interfaces are available, use the left and right arrow keys (or Enter) to switch between them.

Press q or Ctrl + C to exit.

Checking Bandwidth Through Your Cloud Provider's Control Panel

Most cloud providers include built-in bandwidth monitoring tools within their management dashboards. This is often the simplest way to monitor cloud server bandwidth without installing additional software.

Real-Time Bandwidth Graphs

Cloud platforms such as DigitalOcean, Linode, and Vultr provide real-time inbound and outbound bandwidth charts covering periods such as:

- Last 6 hours

- Last 24 hours

- Last 7 days

- Last 14 days

These visual dashboards make it easy to identify traffic spikes and usage trends.

Detailed Ingress and Egress Metrics

Major cloud providers such as Amazon Web Services (AWS), Microsoft Azure, and Google Cloud Platform (GCP) offer advanced network monitoring services.

Examples include:

- AWS CloudWatch NetworkIn/NetworkOut

- Azure Monitor Network Metrics

- Google Cloud Monitoring

These services allow users to:

- Visualize traffic patterns

- Configure alerts

- Export data through APIs

- Analyze network performance over time

Monthly Bandwidth Usage Reports

Cloud management panels typically display monthly bandwidth consumption, particularly outbound (egress) traffic.

Platforms such as DigitalOcean provide visibility into:

- Total bandwidth allocation

- Data consumed (GB/TB)

- Remaining bandwidth quota

- Potential overage charges

Monitoring these metrics helps organizations avoid unexpected cloud networking costs.

Conclusion

By using tools such as iPerf3, Speedtest CLI, Nload, and cloud provider monitoring dashboards, administrators can accurately measure and monitor cloud server bandwidth from multiple perspectives.

Regular bandwidth monitoring not only helps identify network performance issues before they become critical but also enables better cost management, especially on cloud platforms that charge based on outbound data transfer.

If you are looking for a reliable, high-performance cloud server platform backed by experienced technical support in Vietnam, Viettel Cloud Server is an excellent choice. Built on Tier III-certified data center infrastructure, Viettel IDC delivers scalable, secure, and cost-effective cloud server solutions for businesses of all sizes.