Subject: RE: [Mip6] review of draft-ietf-mip6-bootstrapping-split-00.txt

From: "Kilian Weniger" <[email-masked]>
Date: Wed, 5 Oct 2005 10:32:49 +0200

> okay, I think we are near to reach an agreement. 
> Kilian, can you please send some text based on James' text so that we
> can close the issue?
> 
> --Gerardo
> 

O.k., I tried to incorporate James' comments. How about the following
text

   Updating the mobile node's FQDN in the DNS with the mobile node's 
   home address has the potential to expose some information about
   the mobile node's location to other nodes if the home agent 
   selected by the mobile node is local, i.e., it is in the serving 
   network access provider's network (that is, the serving network 
   access provider is also acting as the mobility service provider). 

   For three reasons, the risk here is not as deep as known from Route 
   Optimization mode [draft-koodli-mip6-location-privacy-00.txt]. First,

   other nodes usually do not know whether the mobile node's home 
   address belongs to a home agent that is local or remote for the 
   mobile node and, hence, whether the mobile node is really at the 
   location corresponding to the home address. Second, the mobile node 
   (if using reverse tunneling) will effectively appear to be at a fixed

   topological location in the mobility service provider's network 
   regardless of the current mobile node's location. Thus, only the 
   location at the time of bootstrapping would be revealed. Third, 
   depending on the deployment scenario, the geographical area covered 
   by a local home agent (being the "most local" home agent) may be much

   larger than the area covered by an access router. Since the accuracy 
   of the location derivable from the address decreases with increasing 
   coverage, the accuracy may low.

   However, the risk may be high if the mobile node's home agent 
   selection policy is known. If, for instance, the mobile node 
   bootstraps with a new local home agent as soon as moving to another 
   network to improve routing efficiency of future communication 
   sessions in Bi-directional Tunneling mode, other nodes are able to 
   track mobile node's movement to some extent by constantly querying 
   mobile node's DNS entry. 

   To mitigate the risk, the mobile node should either not request DNS 
   update or be careful to select a home agent that is not within the
   serving network access provider's network. 

The text may also be applicable (with some changes) to the solution
draft for the integrated scenario.

Kilian

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From: "James Kempf" <[email-masked]>
Date: Wed, 5 Oct 2005 09:20:15 -0700

I think I can agree to this with one exception (marked with jak>> below:

jak>> The selection of HoA in and of itself doesn't reveal much about the 
location even at the time of bootstrapping. So I'd like to see this sentence 
("Thus...revealed.") dropped.

Rest of it is OK.

However, before we put this text into the document, I think we need to 
decide whether or not we are going to resolve Issue #53 in favor of removing 
local HA naming from the split scenerio draft or in favor of keeping local 
HA naming in and defining a cannonical local HA naming convention for 
interoperability. If we decide in favor of removing, then I think we should 
save this text and put it into the integrated scenerio draft.

                        jak

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From: Vijay Devarapalli <[email-masked]>
Date: Wed, 05 Oct 2005 14:20:02 -0700

James Kempf wrote:
> jak>> The selection of HoA in and of itself doesn't reveal much about 
> the location even at the time of bootstrapping. So I'd like to see this 
> sentence ("Thus...revealed.") dropped.
> 

sounds good to me too.

Vijay