I have this Smoothwall VM set up on my Arch linux server. The Arch linux server is on the GREEN network(behind the firewall) and a Slackware computer on the RED network. The GREEN interface gateway IP is 172.20.1.1, and the Arch server is 172.20.1.100. The RED network is 192.168.0.x.

I'm a little confused about Smoothwall's settings. First of all, I should mention that pinging the Arch server(172.20.1.100) results in a 'Destination Port Unreachable' error. from the RED network I can ping everything else, including the gateway(172.20.1.1). Not exactly sure if this is normal.

Second, if I look in advanced settings in the networking tab, there's an option to block Pings. Yet it only seems to work on the gateway(172.20.1.1). So checking this setting prevents pings to the gateway, but I can still ping the Arch server, although I still get the Port Unreachable error.

My setup seems like a mess at the moment, and I'm wondering how much of this is normal.