[betaby]

> ISPs can CGNAT for cheap

Not really that cheap. While CPAEX is CAPEX, OPEX is still a thing and operating CGNAT requires efforts. Also some (most?) CGNAT implementations are buggy and is not a good user experience, even for users who don't understand the concept of IP at all.

[jeroenhd]

> Also some (most?) CGNAT implementations are buggy and is not a good user experience, even for users who don't understand the concept of IP at all.

They're a pain, especially when you're visiting a website with CAPTCHAs, but the money they save on buying IP space seems to be worth the bad experience from an ISP point of view.

Even here in the Netherlands, with its relatively high wages, a fiber ISP decided to use CGNAT on their new fiber networks as a cost-cutting measure. Luckily, customers can disable CGNAT in their online control panel, but the cost cutting measure seems to be worth the annoyed customers from that company's perspective at least. Of course they also didn't roll out IPv6.

[Tijdreiziger]

Assuming you’re referring to Delta/Caiway… I think they’re expanding quite quickly, considering both started out as smaller local ISPs; so it’s probably between CGNAT and having to acquire IP space for them.

The fact that they’re owned by an investment fund also makes them probably very focused on profitability.

As a point of comparison, the other players aggressively rolling out fiber (KPN, ODF/Odido) have been nationwide ISPs since the 90s, and they aren’t doing CGNAT AFAIK (so they probably aren’t hurting for IP space).

[jeroenhd]

I fully understand their choice to default to CGNAT because of their rapid expansion and the lack of available IPv4 space. However, if they have the money to invest in ISP grade CGNAT equipment, adding IPv6 shouldn't be a big problem.

Ziggo's DS-Lite, which also CGNATs IPv4 traffic, is annoying but at least you get a normal IPv6 subnet. This would've been a much better solution looking forward.

Dutch ISPs in general have plenty of space. Dutch ISPs has 53 million IPv4 addresses for a country of 18 million according to the first result on Google. Every person in every household can have a home connection and two servers without anyone lacking IPv4 addressing if these addresses were all pooled together.

However, there's no guarantee that things will stay this way. Like I said, Ziggo already does a form of CGNAT, and as the price of IPv4 addresses keeps rising, I expect more cheap providers to start selling off address space. KPN will stick to normal IPv4 for a while, but I don't trust super cheap companies like Odido to have the benefit of the consumer in mind, especially after trying to route all traffic through their affiliated German exchange instead of AMS-IX a while back. Odido is owned by an American fund as well (which is why they had to change their name), as is VodafoneZiggo.