How can i use iptables on centos 7? [closed]

Answer 1

If you do so, and you're using fail2ban, you will need to enable the proper filters/actions:

Put the following lines in /etc/fail2ban/jail.d/sshd.local

[ssh-iptables]
enabled  = true
filter   = sshd
action   = iptables[name=SSH, port=ssh, protocol=tcp]
logpath  = /var/log/secure
maxretry = 5
bantime = 86400

Enable and start fail2ban:

systemctl enable fail2ban
systemctl start fail2ban

Reference: http://blog.iopsl.com/fail2ban-on-centos-7-to-protect-ssh-part-ii/

Answer 2

Try the following command iptables-save.

Answer 3

RHEL and CentOS 7 use firewall-cmd instead of iptables. You should use that kind of command:

# add ssh port as permanent opened port
firewall-cmd --zone=public --add-port=22/tcp --permanent

Then, you can reload rules to be sure that everything is ok

firewall-cmd --reload

This is better than using iptable-save, espacially if you plan to use lxc or docker containers. Launching docker services will add some rules that iptable-save command will prompt. If you save the result, you will have a lot of rules that should NOT be saved. Because docker containers can change them ip addresses at next reboot.

Firewall-cmd with permanent option is better for that.

Check "man firewall-cmd" or check the official firewalld docs to see options. There are a lot of options to check zones, configuration, how it works... man page is really complete.

I strongly recommand to not use iptables-service since Centos 7