Hi, On Tue, Sep 15, 2009 at 07:43, CentOS List <centoslist at gmail.com> wrote: > How do add a redirect port 26 to 25. I had googled the net and notice that > the syntax is different > > iptables -A INPUT -p tcp --dport 26 -j ACCEPT > iptables -A PREROUTING -t nat -p tcp --dport 26 -j REDIRECT --to-port 25 I suggest you use "iptables" commands to add and delete rules until you set the firewall the way you want, and when everything is ready use the "service iptables save" command, that will write a new /etc/sysconfig/iptables with the current rules you have. That way you don't risk having a syntax error or typo prevent your rules from loading during the next reboot. If you want to preview the new file you can run "iptables-save" that will dump the rules to the console where you can inspect them. I also suggest that you make regular backups of /etc/sysconfig/iptables and that you do a backup just before running "service iptables save" just in case something goes wrong... HTH, Filipe