I am trying to change my firewall machine (RH9 running iptables) such that when it reboots it will still act as I want it to. Currently, after rebooting, the /proc/sys/net/ipv4/ip_forward file contains a 0. I added a line in my /etc/init.d/iptables script in the "start" function to echo a "1" to that file. However, when I reboot, I still see a zero in that file. I added another line in the script to touch a non-existant file as a test to be sure that the start function in the /etc/init.d/iptables script was actually being run at boot time. I then rebooted, still found the ip_forward file to contain a zero, but the file that was touched appeared. Therefore, the start function is being run and the 1 is being echoed to the ip_forward file, but it is being overwritten as a 0 later.
I could simply add a line in my /etc/rc.d/rc.local file to echo a 0 to that file, but I don't want to do that unless I have to. What I want to do at this point is to find out what is echoing the "0" into the ip_forward file after the start function in the iptables script. However, I'm not really sure what the best way to determine this is. In addition, I don't really have any likely culprits in mind to monitor. Can anyone advise me on how to go about hunting this problem down?
Thanks in advance.