I have a mixed set of machines at home (PCs, Macs, etc.) and needed a new wireless router for my home network. After reading a number of good reviews of the Airport Extreme, I bought one.

However, I just found out today that it doesn't support SPI, and will respond to pings from anon sources (i.e. fails the simple firewall tests done by ShieldsUP! and other sites). That's extremely concerning to me - Not that I'm guarding state secrets, but I do log into work from time to time at home.

Are these statements true, or was this for older versions? Either way, do these routers contain something to make me feel a little more secure about using them to protect my home network besides NAT?