Converting an iptables rule to a firewall-cmd rule

Question

I've been working to implement a monitoring software named "logalyze" for a central rsyslog system. For that purpose, I installed a Centos7 server which runs firewalld.

I need to convert below iptables command into a Centos7 firewalld command.

iptables -t nat -A PREROUTING -p udp --destination-port 514 -j REDIRECT --to-ports 1670

This rule is part of a configuration of the central syslog server monitoring specified here.

Answer 1

There are two options you can try,

1. One disable firewalld and start using iptables for some still you get familiar with firewalld. To do so,

   • systemctl disable firewalld
   • systemctl enable iptables (after installing iptables)

You can use iptables commands itself.

2. Second option - Firewalld command

firewall-cmd --permenent --direct --add-rule ipv4 nat PREROUTING 0 -p udp --dport 514 -j REDIRECT --to-ports 1670

Above firewalld cmd will do you the purpose.