Install iperf

sudo yum install iperf3

Launch server with

iperf3 -s 

If you want you can have it bind on a certain interface which can be useful in some causes if you have multiple IP addresses on the system. The IP address is the local address of the machine.

iperf3 -s -B 192.168.1.1

Note you may need to disable the firewall to allow access from the client

sudo systemctl stop firewalls

From the client computer install iperf and run it.

iperf3 -c 192.168.1.1