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Old 12-13-2004, 01:27 PM   #1
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Persistent iptables? Where to save the script?


First a bit of background: I've had a dedicated server for about 3 years and am used to basic remote adminisitration. The GUI and other features are actually a bit overwhelming...I find myself in terminal pretty often.

At any rate, I'm trying to setup a basic forwarding for my home network. It's run of the mill and it works but is not persistent after reboot or restart. Here is the script I'm using (courtesy of
# Delete and flush. Default table is "filter". Others like "nat" must be explicitly stated.
   iptables --flush            
   iptables --table nat --flush
   iptables --delete-chain     
   iptables --table nat --delete-chain

   # Set up IP FORWARDing and Masquerading
   iptables --table nat --append POSTROUTING --out-interface eth0 -j MASQUERADE
   iptables --append FORWARD --in-interface eth1 -j ACCEPT

   echo 1 > /proc/sys/net/ipv4/ip_forward
Right now I have it saved as an executable and if I reboot I come back and execute. The question I have is how do I execute this script at boot? Can I include it in a rc.d/file?

Now, I want to apologize to all the vets for such a simple question. I have UFSB and read 14 pages of threads as they releate to "gateway". Most are asking how to troubleshoot their networks and iptables for access. I did not find one explaining how to make a currenty working homenetwork persistent after reboot.

I am using CentOS v3.3 with 2 NIC's. eth0 -> internet, eth1 -> internal

All settings are good on boot (homenetwork functional, external access is good) but the forwarding has to be setup with the script above.


Old 12-13-2004, 01:41 PM   #2
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Registered: Apr 2003
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Distribution: Kubuntu, Debian, Knoppix
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Well.... I have that kind of stuff (things that have to happen at boot time) at the rc.local file. I think that's the quasi-standard place to do that (in a RH-based distribution).


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