How can i use iptables on centos 7?

I installed CentOS 7 with minimal configuration (os + dev tools). I am trying to open 80 port for httpdservice, but something wrong with my iptables service ... what's wrong with it? What am I doing wrong?

# ifconfig/sbin/service iptables save
bash: ifconfig/sbin/service: No such file or directory

# /sbin/service iptables save
The service command supports only basic LSB actions (start, stop, restart, try-restart, reload, force-reload, status). For other actions, please try to use systemctl.

# sudo service iptables status
Redirecting to /bin/systemctl status  iptables.service
iptables.service
   Loaded: not-found (Reason: No such file or directory)
   Active: inactive (dead)

# /sbin/service iptables save
The service command supports only basic LSB actions (start, stop, restart, try-restart, reload, force-reload, status). For other actions, please try to use systemctl.

# sudo service iptables start
Redirecting to /bin/systemctl start  iptables.service
Failed to issue method call: Unit iptables.service failed to load: No such file or directory.  

With RHEL 7 / CentOS 7, firewalld was introduced to manage iptables. IMHO, firewalld is more suited for workstations than for server environments.

It is possible to go back to a more classic iptables setup. First, stop and mask the firewalld service:

systemctl stop firewalld
systemctl mask firewalld
  

Then, install the iptables-services package:

yum install iptables-services
  

Enable the service at boot-time: IT网，http://www.it.net.cn

systemctl enable iptables
  

Managing the service

systemctl [stop|start|restart] iptables
  

Systemctl doesn't seem to manage the save action like you were able to do in the past with service:

/usr/libexec/iptables/iptables.init save  

This fixed it: Linux学习，http:// linux.it.net.cn

yum install iptables-services
systemctl mask firewalld
systemctl enable iptables
systemctl enable ip6tables
systemctl stop firewalld
systemctl start iptables
systemctl start ip6tables