# disable firewalld
systemctl disable firewalld.service
systemctl stop firewalld.service
# enable iptables
systemctl enable iptables.service
# configure firewall rules using lokkit
# creates /etc/sysconfig/iptables file
system-config-firewall
# Reboot (Just to make sure)
# Verify with:
iptables -t filter --line-numbers -vxnL
# Shows running service and recent logfile entries:
systemctl status iptables.service
# Lists iptables rules:
/usr/libexec/iptables/iptables.init status
# To get rid of errors:
# iptables -m state -state=NEW not supported
# Change iptables rules from:
-A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
-A INPUT -m state --state NEW ...
# to:
-A INPUT -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT
-A INPUT --match conntrack --ctstate NEW ...
# Admin tool, show IPTables State:
iptstate
# Optional for HA:
yum install conntrack-tools
# show conntrack table:
conntrack -L -o extended