Well im experiencing the same sort of problem as you, I have just installed smoothwall onto a 486 pentium 100 with 48mb Ram and 2gb hard disk.
I also can connect to the box via my browser but cannot connect to the internet. I am using a internal modem in the smoothwall box.
I have read that I can use that as the RED and I have 1 NIC as my green
If u have n e ideas please can you help
Thanks