If you are not familar with firewalld and the firewall-cmd, check out our Getting Started article.

The --add-rich-rule option is used to add a rich rule. In this example, a rich rule is created so that only one FTP connection is allowed per minue.

firewall-cmd --add-rich-rule='rule family=ipv4 source address=10.17.0.0/8 service name=telnet limit value=1/m accept' --permanent
firewall-cmd --reload

The --check-config command can be used to ensure there are no configuration errors.

~]$ firewall-cmd --check-config
success

firewall-cmd --list-all will show the rich rules.

~]# firewall-cmd --list-all
public
  target: default
  icmp-block-inversion: no
  interfaces: eth0
  sources:
  services: smtp
  ports:
  protocols:
  masquerade: no
  forward-ports:
  sourceports:
  icmp-blocks:
  rich rules:
    rule family="ipv4" source address="10.17.0.0/8" service name="telnet" limit value="1/m accept"