[Swan-dev] public IP's used in testing that we actually squatted on :P

[Paul Wouters]

So rereading the IANA registry and RFCs, it turns out we are squatting
on some IPs :P

Specifically, 192.1.2.0/24 and 192.0.1.0/24

In a further future, I suggest we change these as per:

192.0.1.0/24 -> 192.0.0.0/24
192.1.2.0/24 -> 198.51.100.0/24 or 203.0.113.0/24

Technically, 192.0.0.0/24 is not a documentation test case, the other
three are.

For IPV6, we are good with 2001:db8::/23

But as this will be very disruptive, now is not a good time. So this
message servers partially as a reminder to my future self :)

Paul