I'm unfamilier with RedHat's startup scripts, but I think that their located in rc.x, where X is a number between 0 and 6. The directory that you want is probibly rc.3 or rc.4, find in one of those a file called network or firewall or something like that, and type the above commands into it, and it should load them on startup.
x is actually the Run level in this context
An alternate method to this ( rather then randomly guess some rc.x folder to put a script in ) is to edit /etc/rc.d/rc.local. This runs after the start up of the Linux is complete and is a good time to execute custom script.
You could enter what was suggested by Clark into /etc/rc.d/rc.local how ever this assumes that you are running iptables and you may not be. if you don't you will need to put "modprobe iptables" as the line preceeding his suggestion. I am pretty sure that by default iptables will be running. My red hat box won't let me turn the it off even when disabled in the config. :-/ how ever rmmod is my friend in this instance
If Internet Sharing still fails there are severl things to check.
1) Firewall Rules. If you have set up a firewall on the linux box and it doesn't allow any traffic through the fire wall then internet sharing is not going to work. Firewall SYN packets only ( which are used to initiate TCP/IP connections ) for ports you need your amiga to access the internet via your Linux box. This will allow returning "masqueraded" traffic through the firewall while keeping out nasty traffic from the outside.
2) Make sure that iptables is actually running. Type "lsmod" and make sure you see the following
ip_tables
iptables_filter
3) check that the script Clark has suggested is actualy changed the ip table. You do this by typing "iptables -L" ( case is important). You should see some rules from the the Clark solution listed. If you get an error that talks about IPTABLES not being compatible with your kernel thn iptables is not running. See point 2.
if this failes pop me an email at ronybeckatozemail.com.au
Hope this helps
