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mightym1
03-01-2005, 03:39 PM
Hi All,
I'm looking for suggestions as to what would have caused the following problem:

Firewall/Gateway:
RH9 Box running GShield
IPTables 1.2.7a
IPChains 1.3.10
eth1 = Internal Interface (192.168.1.1)
eth0 = External Inferface (Static External IP)

This setup has been working perfectly over the past year. Custom logging has allowed me to track problems on the internal network, and avoid service interruptions from my ISP!
Today I decided to reboot the machine as I hadn't rebooted in over a month. The only un-implemented change to the sytem was a single iptables rule to allow outgoing SMTP connections to a new mail server.
Upon rebooting, nothing is getting passed over from the Internal (Eth1) to the External (Eth0) interfaces.
I tried removing the new iptables rule, reloading, rebooting, removing all rulesets, reloading, rebooting, and still I'm getting the same results. There are no errors being reported in any of the logs as well.
When I try an "iptables -L" it looks like my Input chain has changed a quite a bit. There are now a bunch of entries that look like:
Multicast 224.0.0.x
Despite the changes to my input chain, all of the other rules are still there, and they look as if they are in the proper order as well.
One other item to note is that when I do an "iptables -L" it is now taking a very long time (~20 minutes) to display the entire list.

Any help, ideas, or pointers in the right direction will be greatly appreciated!

Thanks in advance,
M.G.

retsaw
03-01-2005, 08:57 PM
Have you set up IP forwarding?

Do "echo 1 >/proc/sys/net/ipv4/ip_forward" as root to enable it. It is probably not enabled by default, unless you have a script that does it when you boot your box or perhaps as part of a firewall script or something.

mightym1
03-04-2005, 07:03 PM
Yes, IP Forwarding is enabled.

The box has been running fine for over a year! Still unclear as to how this could have happened unless someone got in and made changes, although I can find no traces on the system of such activity.

I think my next step is going to be to replace the network cards to see if it's a hardware problem or some sort.

Thank you for the reply...

Anyone else? Ideas? Guesses?