Master Network Speed Testing with iPerf: Installation, Commands, and Advanced Options

iPerf is a network performance testing tool used to measure maximum TCP and UDP bandwidth. It supports multiple platforms including Windows, Linux, and macOS.

Installation

On Linux, use the package manager. For Ubuntu/Debian:

sudo apt-get update
sudo apt-get install iperf

On RPM‑based systems such as CentOS or RHEL:

sudo yum install epel-release  # install EPEL repository
sudo yum install iperf

For CentOS 8 / RHEL 8, replace yum with dnf:

sudo dnf install epel-release
sudo dnf install iperf

On macOS, install via Homebrew: brew install iperf On Windows, download the pre‑compiled binary from the official iPerf website.

Using iPerf

iPerf usage consists of two steps: start the server, then run the client.

Server

Start iPerf in server mode (default listening port 5001):

iperf -s

The server waits for client connections.

Client

Connect to the server from the client: iperf -c <server_ip> Example:

iperf -c 192.168.178.223

This connects to the server at the given IP and begins the test.

Advanced Options

Common iPerf options include: -i <interval>: set reporting interval in seconds. -n <bytes>: specify total number of bytes to send. -t <time>: set test duration in seconds. -u: use UDP instead of TCP. -p <port>: set server listening port. -P <parallel>: run multiple parallel streams.

Examples

Run a 10‑second TCP bandwidth test: iperf -c 192.168.178.223 -t 10 Run a 30‑second UDP test: iperf -c 192.168.178.223 -u -t 30 Send 1 GB of data: iperf -c 192.168.178.223 -n 1g Report results every 5 seconds:

iperf -c 192.168.178.223 -i 5

Summary

iPerf is a powerful network diagnostic tool that can test TCP and UDP bandwidth, providing reports on throughput, latency jitter, and packet loss. By configuring parameters such as server/client IP, port, test duration, and reporting interval, users can obtain accurate performance measurements.