The firewall rules will only be active if the iptables service is running. To manually start the service, use the following command:
/sbin/service iptables restart
To ensure that iptables is started when the system is booted, issue the following command:
/sbin/chkconfig --level 345 iptables on
You can also use the Service Configuration Tool to activate iptables. To do so, see the Official Red Hat Linux Administrator’s Guide.
You cannot run the ipchains service along with the iptables service. To make sure the ipchains service is disabled, execute the following command:
/sbin/chkconfig --level 345 ipchains off