BBC News - 'Fresh proposals' planned over cyber-monitoring

Peter Fairbrother zenadsl6186 at
Sun May 12 15:39:42 BST 2013

On 12/05/13 10:07, Florian Weimer wrote:
> * Charles Lindsey:
>> But I thought IPv6 did reserve a batch of numbers that would map into
>> the IPv4 space (but not at the "bottom" of the IPv6 range).
> There are at least three different reserved /96 prefixes for mapping
> IPv4 addresses.  Except for the deprecated ::/96 prefix, these
> mappings are incompatible with the IPv6 address architecture and its
> requirements on the structure of global unicast addresses, so their
> use on the IPv6 Internet is not permitted.

I thought the 64:ff9b prefix was routable in IPv6?

Mind, I think IPv6 is a horrible kludge with no advantages (apart from 
the larger address space, which could easily be done with a small 
extension to IPv4) over IPv4, and should be aborted.

Of course IPv4 is a bit of a kludge too, especially nowadays as the 
original model has been distorted because of the lack of address space - 
NT is not natural, and assigning port ranges to subscribers breaks 
something, if only the notional "ip address is for a machine, port is a 
process on that machine" model - but at least it works.

Is the IPv4 240./8 range still reserved? Just start all IPv4e (IPv4 
extended) addresses with that and make them 10 bytes long, it won't 
break much.

Hmmm, is 64 (or more realistically 48) bits enough for the routing prefix?

-- Peter Fairbrother

More information about the ukcrypto mailing list