sudo yum install iperf3
Launch server with
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