Re: Chairs Review on <draft-ietf-6man-predictable-fragment-id-02>

[Bob Hinden <[e-mail]>]

Fernando,

> On May 29, 2015, at 1:15 AM, Fernando Gont <[e-mail]> wrote:
> 
> Hi, Bob,
> 
> On 05/19/2015 05:40 AM, Bob Hinden wrote:
>>>>>> In Section 2 "Security Implications of Predictable Fragment
>>>>>> Identification values”.  The problems listed seem to us to
>>>>>> be overstated.  As the draft notes later, the issue with
>>>>>> predictable fragment IDs in IPv6 is only an issue for IPv6
>>>>>> packets with the fragment header.
>>>>> 
>>>>> Yes, but you can trigger fragmentation for any traffic flow
>>>>> (see draft-ietf-6man-deprecate-atomfrag-generation).
>>>> 
>>>> 
>>>> Yes, if it knows the address of the other side of the
>>>> connection. The attacker would have to be on link, or monitoring
>>>> the traffic between the two hosts.  This make this attack much
>>>> harder in practice for an off link attacker.  If on link, then
>>>> there are so many better attacks.  Hence my comment of the
>>>> problem being overstated.
>>> 
>>> It is trivial to know the IPv6 addresses involved for many
>>> scenarios. e.g. BGP peer to BGP peer, secondary DNS to primary DNS,
>>> SMTP server to SMTP server, etc.
>> 
>> That’s my point.  It’s trivial only if you know the addresses of both
>> side of the connection.  It effects well known nodes.  It does not
>> affect the vast majority of hosts on the Internet.  Hence, I think
>> the text should accurately describe the risk.  I think the current
>> text overstates the problem.  You could say something like you did
>> above.
> 
> I've added text along these lines and rev'ed the I-D.
> 
> P.S.: Ready to ship now?

I will take a look.  This was the last issue I had.

Thanks,
Bob