Probably the same day that the Voyager spacecraft finally leaves the Solar system. What I mean by this, is that the line is really fuzzy -- you can always buy a block of IPv4 addresses, if you pay enough.

It becomes more and more impossible every day.

Last time I tried to acquire a new IPv4, the distributor (my VPS host) required a technical reason for the request. If the request wasn't up to par, you would be denied an IPv4 + given an IPv6.

15 years ago I had to fill out an IP justification form - the justification was I had multiple SSL sites that all needed separate IP addresses. Wasn't a big deal, but was told it was standard practice (it was a smaller server center). And then I've had other dedicated server companies give me a block of 8 (5 usable) as just part of the monthly price.

What seems so wasteful is the "3 unusable" out of the 8 that are allocated. I have a vague understanding that those 3 are used for some routing/addressing stuff internally, but it's always felt incredibly wasteful.

You can actually use two of these addresses (network & broadcast) - but you cannot really call it a proper /X block anymore. You will also have to make sure to disable the broadcast address you've used up on all of your hosts.

This is all very fuzzy and some admins will look at you weird for doing this - but sometimes you've gotta do what you've gotta do.

The third address (router) is actually used by your ISP's router's to reach your subnet.

I set up a dedicated server a few months ago. I was given, without even asking for it, a /29 (sort of 8 IPs), and could pay more for additional ones with justification like wanting one per virtualhost, etc.

This was not at a particularly expensive provider.

It's trivial to get new IP4 addresses on AWS and Rackspace. I guess it depends on the company. Microsoft's Azure does a weird thing where instances all share the same IP but are accessible via different ports when in a group.

Depends on the RIR that assigned your block. RIPE For example requires you provide a technical reason, AWS gets around this by saying that technically every instance could have an SSL certificate and thus should have it own IP for compatibility reasons. RIPE will and has reclaimed /24's and /16's from LIRs who didn't follow their guidelines (tl;dr of which is "must be a technical limitation of IP sharing")

And XP is already out of support and Server 2003 will next year. When will Amazon AWS end support?

So they could recall most of Amazon's IPs due to lack of SSL? Fun to watch!

Have you ever been denied? My understanding is that hosts are required to justify usage, but that they aren't exactly scrutinizing that document.

Hasn't that been the case for a long time? I'm pretty sure I remember seeing stuff along the lines of, "If you'd like an additional IP address for your server, contact us and tell us why you need it" a decade or more ago.

When I changed my home provider 6 months ago I didn't get a real static IP by default. I had to call them and explain why I would need one to get it. That may not sound like much but here in Bulgaria just a few years ago we used to get 2-5 IPs with faster home plans and 1 with even the cheapest. The pressure is slowly hitting the end users so it can't be that much longer until it becomes cheaper to switch.