I have set up a Centos 7 server to run Nagios. By default the OS has pretty draconian iptables rules and a fellow here suggested fixing this by inputing this command:
iptables -A IN_public_allow -p tcp --dport 80 -j ACCEPT
This works fine until I restart the server, at which point I have to input the command again, otherwise the server is unreachable once again.
Is this normal behaviour for iptables? Can I do something to fix it?
CentOS 7 uses firewalld by default to manage the firewall.
You can simply add the port to firewalld with:
firewall-cmd --add-service=http --permanent # Startup config firewall-cmd --add-service=http # Running config
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