[ Thanks to Veronica for this link.
]
“Q: What are the minimum hardware requirements for pfSense?
“A: The minimum requirements for a pfSense installation are 500Mhz,
128MB RAM, and 1GB hard disk space.“Q: How does pfSense identify and assign interfaces?
“A: pfSense, like any other computer operating system, references
each NIC by some unique value (fxp0, em0, em1, and so on). These
unique identifiers are often associated with the driver being used
and make it easier for us humans to use than the associated MAC
address (00:80:0c:12:01:52). Taking that concept a step further, an
interface is simply a named placeholder for each port: fxp0=WAN,
em0=LAN, em1=DMZ, and so on.”