I am not really sure why ISPs are giving out /48s to customers, even domestic ones all the time. It is rather worrying. At that rate we could be starting to eat the IPv6 address space up after a few decades because of the sheer amount of wasteage. Mind you a change of heart means that the remaining space could be allocated much more responsibly by a policy change later on.
I would have thought that a /60 would be good for most domestic users and a /56 for small businesses unless they have serious expansion plans or there is some risk that they could expand because having to renumber your network because of short-sighted allocation in the first place is fairly unforgivable in my view. Renumbering is just hassle we do not need and a total waste of time and money.
I doubt that I will ever end up with 16 sites or LANs, but in case there could be some phenomenon or development that I cannot see at the moment then perhaps a /56 for me would be slightly safer. But unless I become some kind of vast corporate one day, how am I ever going to end up with 65535 LANs / sites?
Am I just not getting it? AA the ISP has a /32 and that is the standard allocation for an ISP. (I would have thought that some organisations would want some contiguous ones to make a slightly shorter prefix - bigger contiguous address space so as to keep firewalling and aggregation nice and neat.) Basically that means that, unless there are some mini-ISPs, ISPs or other organisations that get a smaller allocation, have to share a /32 each taking a subset of it = getting a longer prefix, then there will only be room for something rather less than 232 ISPs, a bit like the old IPv4 internet but with the unit being 1 ISP not one tin box.
And AA can only have 64k customers then if they are always giving every one a /48 whether they need it or not. If they start to run out then they will have to reduce the over-generous allocation massively, reducing it to /56 gives them room for 256 times more customers or they could start handing out /60s ie 4096 times more customers something like room for 128 million if they changed over st the halfway point.
I wonder what the big ISPs are doing. The likes of BT are going to have to do something more sensible either now or in the future unless they either start out with a bigger allocation from RIPE than a /32, or else they do not follow the standard IMHO dumb advice of giving every user a /48 willy-nilly. I think even BT can work out that they need a lot more than 64k customers, and giving out /56s gives them what 16 million customers which might be risky so if I were BT I would try and get a bigger subnet than a /32 and give out /60s and /56s with /48s to business users who are actual companies or users who have any risk at all of serious growth.