How to obtain multiple IPs and assigning them to VPSs using only 3 port Alix?

[torontob]

Hi Everyone,

My provider gives me a block of /27 which is 32 IPs with broadcast and network addresses.

I have a server that is running 20 different virtual private server in Xen (CentOS). I have an Alix2d13 which has 3 ports on it.
I also have a dumb switch with 8 ports on it. My internet provider gives me one RJ45 link to come into my pfSense (alix2d13) and then from there I want to obtain all the IPs and then assign them to many different virtual private server which are indeed into one single server. That server has eth0 and eth1.

How can I obtain all of the /27 and then separate them into networks of their own with full firewall capabilities and yet assign them directly tothe VPSs? am I fantasizing here or do I need a managed switch with 20 NIC cards on the server and 20 NICs on the pfSense router for this to work?

Thanks