Extreme Newb here so please be kind. My office is full of Macs and Windows boxes. My IT staff and I only "dabble" in Linux when we get a chance.
So, we're trying to build a simple Firewall/Gateway out of Ubuntu. We have a machine with 2 NICs running the latest version: 10.04.
We have been able to set up the gateway/routing fine using both the built in Internet Connection Sharing as well as using Guidedog. The current setup we are testing is using Guidedog.
For the NICs we have set eth0 as our internet connection and eth1 connects to the LAN. We've manually set all IPs...no DHCP at this time.
Next we try to install a firewall. We have tried both Firestarter and Guarddog. After setup with either, the Ubuntu box is still able to get online and access web sites but the LAN gets cut off. No access at all. We are currently running Guarddog and have set the proper protocols (DNS, HTTP, HTTPS) and have also followed the tutorial found here
However, no matter what settings we make as soon as we re-enable the firewall the LAN is cut off. Disable the FW...LAN is back online. We even set up an "Allow All" protocol allowing all ports from 1:65535 and still we get cut off as soon as the FW is enabled.
We saw this same thing happen with Firestarter and my understanding is they're using the same basic Linux FW underneath? SO, what is it we're neglecting to do? Why does the FW completely seal off our LAN connection no matter what we've told it to allow?
Ultimately, here's the layout we're after:
Internet (T1) <> Firewalled Ubuntu <> LAN
Thanks in advance!