This might have been true in the age of modems and two hours of internet access per day, but not any more.
Most people have exactly one device directly connected to the internet (their router), and that router has hours of downtime per year at most. Most of that downtime (if there is any) is due to electricity outages, and so correlated with downtime of other consumers. When there are no outages, very few consumers can be left without an IP address. I'd expect the savings in IP space to be <1%, although I have no hard data here and might be missing something.
This doesn't apply to cellular carriers, there are plenty of subscribers who maintain their plans but disconnect often. This includes people living abroad (who normally use another country's SIM), or even people who turn off their work phones on weekends.
They won't admit it's static, but it is. I've had the same IP for three years since moving into this house. In that time, I've had power outages lasting for days, IP was still the same. I've replaced my router and the assigned IP didn't change. The only way it can change is if they replace their media converter "fiber jack" or you call or go to their store to ask them to change your IP.
My last 3 ISPs in the UK actually specify static IPv4 addresses as part of the service. My current one (IDnet) allows you to buy a block of 5 or so for a small monthly fee too.
In Slovakia one of the biggest networks used to use "almost static" public IPs for home clients, they were assigned by DHCP and cached for 24 hours, so in the few years we've used them our IP changed twice... but since then they switched home customers to IPv6 using DS-Lite so no public IPv4 anymore...
Not only am I getting a static IPv6 address, I configured the address myself from a random number generator and just request it. (Subject to the prefix I'm assigned, but still.) So really I'm being given a very large number of static addresses to do what I like with.
My UK based ISP provides static IPs by default (v4 & v6!). There's a few aiming at smaller niches that do.
We're relatively unique compared to a lot of countries though, where we have an infrastructure provider that serves basically the whole country with very good to tolerable internet (mostly) - Openreach.
Any ISP can sign up to use Openreach's network & a backhaul provider for providing services, and they usually get handover from their backhaul provider in London. Means we have a lot more small/niche ISPs that can still cover the entire country, and provide unique features - like static IPs or even blocks of static IPs.
There are alternative providers too (lots of 'alt-nets', and virgin media) - they're mostly not so open, though.
It used to be common in Estonia, these days I think it's slightly less so, but the price is in the ballpark of five bucks a month to have a static one. It has many good uses and is definitely not a waste if you need it.
It's a waste for the ISP when 99.9999% of users do not need a static IP address. When users turn off their routers they can reassign the addresses to other users. Not to mention the privacy issues of always using the same address.
Who turns off their router? An ISP needs as many IP addresses as they have customers so there's nothing to gain there. I think assigning a dynamic ip is just a way for ISPs to make people pay more to get a static ip.
Well then 99.9999% of the people don't really need it. But if one decides to run their own mail server at home (to save those 5-10-20 per month for their mailbox) it's worth the trade-off.
> Not to mention the privacy issues of always using the same address.
For me that's the thing. Privacy AND Security. Especially when you got something 'listening'/waiting.
That’s not really the same thing though because your ISP doesn’t gain a usable IP while you’re rebooting it.
The only way ISPs would, would be if their customers routinely turned their router off while they’re not using any electronic devices. But even the older generation I know (80+ years old, no “smart” devices apart from a Samsung tablet or a laptop, depending on the individual) don’t turn their routers off. It’s just not something people do.
In fact if anything, the kind of people who might want to are likely the same kind of people who would get scared to in case it broke something.
The only class of people I think who might, would be ultra tin foil hat paranoid people. And that’s certainly not going to be a large demographic.
So when was the last time you checked for patched-but-not-auto-applied vulnerabilities in your (almost certainly ISP-provided) router?
ISPs don't want things to randomly break for consumers, so are likely to avoid rolling out updates that could potentially go wrong, but all code has vulnerabilities, and this controls access to your internal network.
I think that's too much 9s if you consider everyone who would run a home minecraft server or some other small scale personal server if having a static publicly addressable IP was easy and simple.
In Denmark you can normally buy it for a small extra fee. My previous ISP didn't really understand the meaning of a static IP and announce that after having performed service in the area any customers with static IPs would get a new IP... making it specifically not static.
Most normal households don't get static IPs, but on the other hand they change very infrequently, so they are practically static.
The ISP that services our apartment building has static IPs available. Residential and commercial are just billing SLAs. The actual network equipment treats you exactly the same. It's not like they are rolling a separate fiber for ground floor commercial and residential services.
