On Fri, 18 Jul 2014 15:45:29 -0700, Owen DeLong said:
On Jul 18, 2014, at 11:32 , Jay Ashworth <jra@baylink.com> wrote:
"The Internet as "the largest equivalence class in the reflexive, transitiv e, symmetric closure of the relationship 'can be reached by an IP packet from'" -- Seth Breidbart.
Note that the sentence is incomplete and as soon as you put something after "from" that is actually meaningful, you end up with different answers for the left hand side of that statement depending on what you put at the right hand side.
Which is why Jay said "closure" - that means (basically) "across *all* meaningful right hand sides, plus nay *new* ones that pop up as previously undiscovered left hand sides along the way. And yes, this definition *does* mean that if you find a reachable webserver in a corporate DMZ, and that webserver can reach machines that are behind the corporate firewall, those supposedly firewalled machines are "on the internet" as well. Which is what your security geek was trying to explain to you :)