Well, our router with firewalling and virtual private networking is quite complete. We've build a complete Linux distribution from scratch, which allows us to use a famous gaming console as a software router. We've compiled everything we need from scratch: Beginnig at the first toolchain and ending up to the source code implementing the SSH protocol.
But, we still miss one thing: A persistent configuration. Every time we're rebooting, we'll loose out configuration until we burn a final configuration to a CD-R. But, you'll agree, when is a configuration final?
So, the last chapter describes, how to use the VMU for storing configuration files.