Sky blocks Newzbin, important legal and technical questions need answering

Ian Batten igb at
Fri Dec 16 19:57:55 GMT 2011

On 16 Dec 2011, at 1246, James Firth wrote:

> Ian Batten wrote:
>> ... there's no reason for a small hosting company to allocate each
>> customer a /64 ...
> AFAIU there is. RFC2373 reserves those bits for interface identifiers
> (obviously a privacy nightmare)

Why would it be a privacy nightmare in a co-lo?  And outside a co-lo, RFC4941 solves the problem and is the default on both OSX (10.7 and on; you have to enable it on 10.6) and on XP SP3 onwards.  I presume Linux gets it right (/proc/sys/net/ipv6/conf/all/use_tempaddr). 

> and RIPE IPv6 Address Allocation and
> Assignment Policy (ss5.4.1) states 
> "The size of the assignment is a local decision for the LIR or ISP to make,
> using a minimum value of a /64 (only one subnet is anticipated for the End
> Site)."
> Therefore it would be reasonable for any network blocking of IPv6 to block
> with a mask of /64.

But there's no reason for a hosting company to use blocks at all.  As of today, if you buy a simple hosting arrangement, you get a single IP number for your single host.  Why would you expect, or need, more than a single IP number within your co-lo's network?   They might opt to give you a /64, they might opt to allocate IP numbers within a /64.  Otherwise IPv6 because essentially 64 bit, rather than 128 bit, addressing, as the top 64 bits are used to allocate /64s and the bottom 64 bits are used to allocate one host.   


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