iperf error: connect failed: no route to host

[Description]

      when you execute command iperf -s  on one system and iperf -c x.x.x.x  on another system. It comes out error "connect failed: No route to host" as follows.

[Procedure]

Step 1: Display the status of firewalld

firewall-cmd --state
running

Step 2: Turn off firewalld

# systemctl stop firewalld.service 

Step 3: Check the status of firewalld

# firewall-cmd --state
not running