whats a good security Router with a configurable SPI Firewall which also blocks all internet threats? and has mac address spoofing
Even the most basic of home grade routers have SPI (which isn't all that important..it's very basic, it's the NAT that counts), and MAC spoofing (which you don't need much anymore with most ISPs, learn to flush the MAC address memory in the modem properly, and you can switch your WAN device any time you want).
