VPN hacks, ipv6, and then some

I'm completely overwhelmed by things I'd like to learn and do.

My current project has to do with the idea of having multiple VPNs enabled
on the same machine, while having the choice of what application should
use what VPN.

To give the idea, one should be able to use two networking programs at the
same time, while appearing with different ip addresses on the Internet.

Why?  I don't know.  The best reason to do this I could come out with is
"to troll better in IRC".  The reason why I do it is "because I [think]
I can".  And also because I want to gain the knowledge in networking
that allows me to do it.

It is true that it's hard to gain knowledge in the networking department,
unless you work in the field.  It is much easier, by comparsion, than
gaining knowledge in computer programming!

For instance, one doesn't often work with network equipment: it is
typically pointless to have something more expensive than a home router,
at home!  Or, how do I get experience in IPv6 if my provider only routes
IPv4 traffic?

Yet, if I don't know IPv6, how can I notice that -say- my firewall
rules only apply to half of my network stack?