Data held by ISPs

Roland Perry lists at
Sun Dec 28 16:47:31 GMT 2014

In article <AD0AB2BB-D50A-4581-9CD4-BDA1C5F7F8D9 at>, Ian 
Batten <igb at> writes
>> When IPv.6 really gets going I suspect that most IPs will be fixed.
>It depends on what you mean by "most".  Most fixed line (DSL, Cable, etc) will be fixed, because
>ISPs will probably get one or more /40 and therefore will obtain addresses in blocks of 2^24.  Very
>few ISPs have more than 16 million fix-line customers, and the few that do will have either multiple
>/40s or something larger.
>However, the mobile operators will probably use SLAC or DHCPv6 to allocate addresses within a single /64
>per [some network organisational block], and most mobile devices use RFC 4941 privacy extensions
>(and sometimes can't turn them off: I get really annoyed that all the iDevices at home get fresh
>IPv6 addresses every hour).  Given |mobile devices|>|fixed lines|, most IPs will in fact be dynamic.

Does that mean that if I use an IPv6 mobile dongle to get my Internet 
Access that they won't be providing me with a /48 to play with?

I was under the impression that end-points in most of the RIR regions 
needed special permission to be issued with less than that.
Roland Perry

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