Re: draft-ietf-v6ops-cpe-simple-security: filtering encapsulated flows

[Brian E Carpenter <[e-mail]>]

On 2009-08-23 21:15, Mark Smith wrote:
> On Sat, 22 Aug 2009 22:33:37 -0700
> james woodyatt <[e-mail]> wrote:
> 
>> On Aug 22, 2009, at 21:58, Truman Boyes wrote:
>>> This is quite confusing from an implementation perspective; security  
>>> is not explicitly increased by prohibiting non-encrypted tunnels but  
>>> allowing encrypted (ESP or AH) traffic flows. Wouldn't this simply  
>>> serve as a driver to make all tunnel encapsulations use ESP/AH?
>> Yes.  I'm not sure I can explain how this is supposed to increase  
>> security, but if consensus in the working group emerges around these  
>> recommendations and the draft can proceed through working group last  
>> call, then that's good enough for me.
>>
> 
> Maybe I haven't fully understood the question, however isn't the answer
> as simple as the benefits of IPsec over cleartext? Even the
> better-than-nothing-mode of IPsec, while vulnerable to
> man-in-the-middle attacks during session setup, has a much smaller
> window of opportunity for exploitation over clear text traffic.

Not to mention the fact that other secure VPN techniques such as
IP-over-TLS will still be fine through a conforming CPE.

    Brian