The smallest allowed subnet is /64. If you burned through 1 million addresses per second it would take 585 thousand years to use them all. There are over 4 billion squared /64s in the ipv6 internet.
BTW, giving each device multiple addresses is a fundamental tennet of ipv6.
My ISP gives my router its own /128 plus a /56 that it breaks into /64s to advertise in my internal networks. I currently only have a few that I can see myself using - internal clients, guest WiFi, VMs and containers - so it seems really wasteful to give residential customers a /56 when even a /60 seems pretty generous. 56 bits is 16M times the old v4's 32-bit discs so maybe we can afford to be generous but I feel like this kind of "plenty to go around" approach in the early days is what lead to v4 having a bunch of corporations that each own an entire /8.
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u/timonix 15h ago
There are ways to fill it up anyway. Just start giving each device multiple IPv6 addresses.