Last updated on November 1, 2018
I've been delving into the wonderful word of networking (lol) and I have a few questions of clarification for IPv4 subnetting.
I'm pretty comfortable with the idea of subnetting. I understand that it's a way of splitting up an IP address into public/local addresses. From my experience though, the only time I've seen this used is in private networks (10.x.x.x, 198.162.x.x, etc).
How does subnetting work for public IP addresses? For instance, if I'm running a datacenter, would owning 220.127.116.11/16 be equivalent to owning the ~65000 addresses between 18.104.22.168 and 22.214.171.124?
As a follow up, do ISPs use this as a convenience for routing purposes?
I ask this because working with AWS, as far as I'm aware its not possible to allocate consecutive public IP addresses for public subnets. I'm building a public subnet, filling it with machines running an API, and would like each machine to have a consecutive public IPs within the subnet. Am I correct in assuming this isn't possible?
I understand IP allocation in AWS is in its own little world (since you're basically borrowing IPs that Amazon had previously purchased) and that it may be different everywhere else.
Apologies for the noob question :)
EDIT: 65000 not 600000