After searching previous questions here, the general consensus seems to be if an instance that I own is assigned a private IP of 10.208.34.55, that only OTHER INSTANCES I OWN can reach it at that address. See:
Is that correct? So I can treat all my instances as if they are on a LAN and authenticate and trust any machine coming from 10.XXX.XXX.XXX because I am sure I own it?
I just want to be sure. I'm finding that amazon seems to be rather more interested in waxing poetic about The Cloud and their 3-character abbreviations than actual providing clear technical documentation.