Linux systems administrators and network administrators often find diagnosing network speed degradation complicated, as there are very few tools available to diagnose these issues. iPerf is a command-line tool used in the diagnostics of network speed issues.
iPerf measures the maximum network throughput a server can handle. It is particularly useful when experiencing network speed issues, as you can use iPerf to determine which server is unable to reach maximum throughput.
You can use apt-get to install iPerf on Debian and Ubuntu:
apt-get install iperf
For CentOS
CentOS repositories do not have iPerf by default. Use the EPEL repository, which is a repository used to install third-party software packages on RedHat systems such as RHEL and CentOS:
yum install epel-release For Both
yum update yum install iperf