I am searching for a firewall product (appliance or software) for an hosting/housing environment. The biggest problem is that the rules get very complex as more customers are behind the firewall. Some have only one server, others have a whole subnet. Some need NAT, some a VPN endpoint. Some customers want to only allow port http, others ssh as well. So the device needs to be able to support VLANs and it should be possible to group the rules per customer.

Speed is another important point. And being able to manage redundant devices easily.

I am searching for something that doesn't have all the extras like spam filter etc. I was searching a lot on the net but either they had all those extras as well (and with is an overloaded configuration interface) or they missed some of the features I need (e.g. VLAN).

The VPN endpoint is not the an important criteria. We were thinking about a separate machine for it.