Today with multi-machine Vbox provisioning I can assume some things about the network topology because I have control over setting that up (i.e., a common backend subnet with static ips).
Obviously on AWS this is at the mercy of EC2. Is there any good strategy to inform all machines about dns names/ips/etc. of the others so puppet can adjust its configuration accordingly? Is VPC the "right" (and only) way to accomplish this?