Re: [v6ops] Fwd: New Version Notification for draft-collink-v6ops-ent64pd-01.txt

[Fernando Gont <[e-mail]>]

On 21/12/22 04:48, Gert Doering wrote:
> Hi,
> 
> On Wed, Dec 21, 2022 at 08:50:10AM +1300, Brian E Carpenter wrote:
>> There's a reason that
>> https://www.rfc-editor.org/rfc/rfc7421.html#section-4.5 suggests
>> /80 as the reasonable limit for privacy purposes. The issue is
>> making it highly unlikely (and therefore prohibitively expensive)
>> to find an IID by a scanning attack. At /96, the search space is
>> about 4 billion. Given the number of Internet users in the world,
>> and possible applicability of the birthday paradox, that isn't a
>> safe value. (I can't expect to find *your* IID, but I can hope to
>> find *somebody's* IID.) At /80, the search space is about 281
>> trillion.
> 
> What would the benefit be of finding someone's IID, if that IID is only
> valid for a specific prefix?

Well, thatś normally a prerequisite for performing other attacks  -- you 
kind of cannot attack what you cannot find.

That's why IPv6 pentests can be challenging at times....

-- 
Fernando Gont
e-mail: [e-mail]
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