Re: Netflix banning HE tunnels

[Baldur Norddahl <baldur.norddahl () gmail com>]

On 2016-06-13 11:22, Owen DeLong wrote:
> Fine… Consider 2001:0:0:406:0:0:5:302. Owen


That is a Teredo reserved address. Neither option makes any sense 
because it is an invalid Teredo address. You can find examples with two 
equal possible :: blocks but they are actually rare. Try to find one 
that has non zeros in the first 32 bits, as that is usually the case for 
any actually assigned prefix. I hold that for any actually assigned 
prefix, it will almost always be the first possible :: block that makes 
sense - prove me wrong.

Consider:

2001:db8:1:2:3:4:5:6

Provided that the first two 16 bit blocks are non zero, there can only 
be multiple equal runs of zeros if the run length is 2. This follows 
from the rule that disallows shorting out a single :0:.

Now this leaves the following:

2001:db8:0:0:1:1:0:0 => 2001:db8::1:1:0:0 is most sane because this 
would usually be host 1:1:0:0 in prefix 2001:db8::/64.

2001:db8:0:0:1:0:0:1 => 2001:db8::1:0:0:1 for the same reason.

2001:db8:1:0:0:1:0:0 => 2001:db8:1::1:0:0 because this is host 1:0:0 in 
the prefix 2001:db8:1::/64

And that was all possible ways you can have multiple :: blocks in an 
actually assigned prefix.

Regards,

Baldur