On 18 Feb 2004, at 13:06, Tom Petch wrote:
I find your definition of the Internet delightfully ambiguous. I was
taught that the Internet (as opposed to an internet or the internet)
was
the public network accessible through public IPv4 addresses (this
predates
IPv6) ie the Internet ceased at a firewall or other such IP level
gateway.
I'm not sure who teaches that, but that's an extremely weak definition.
Define "public network". Define "accessible". Define "public IPv4
addresses". Note that even with definitions, the resulting "Internet"
is subjective in the sense that the shape of the network changes
according to the perspective gained from local connectivity (so one
host's Internet is different to another host's Internet).
The idea that the Internet is properly partitioned between devices
which block packets would these days mean that in reality today it
rarely extends beyond a single autonomous system, and often not beyond
a single router. This is not, to my knowledge, a common definition (and
even if it was common, it hardly seems very useful).
Lots of people seem to enjoy being needlessly pedantic about "the
Internet" vs. "the internet" vs. "an internet", regardless of the fact
they are unable to cite a reason for the distinction. So that's at
least a common distinction, albeit arguably a fairly pointless one.
Q: "But what *IS* the Internet?"
A: "It's the largest equivalence class in the reflexive transitive
symmetric closure of the relationship 'can be reached by an IP packet
from'." - Seth Breidbart
Joe