Subject: Re: [MOBILE-IP] Rough Consensus for Option 2 (Private addresses in Mobile IP)

From: Gabriel Montenegro <[email-masked]>
Date: Thu, 11 Nov 1999 08:18:18 -0800

i think this consensus on #2 (reverse tunneling support for private
addresses) solves many problems despite its
limitations.

the fact that deploying a solution based on reverse tunnels would rely on
at least some nodes having a globally routable address space is not
much of an limitation, because nobody knows how to route in an internet
that lacks such a feature anyway (see draft-ietf-iab-ntwlyrws-over-01.txt).

it also relies on layer 2 for disambiguation of mn traffic
and security. but this is ok for cellular technology, undoubtedly
the most important deployment driver for mobileip.

given the limited scope of a solution based on reverse
tunnels, it would be relatively
simple to add a section to rfc2344version2 on this scenario
and its limitations. alternatively, it could go into a new
document on "limited" support for private addresses.

what do the wg and chairs think?

-gabriel

>>
>>At IETF45 in Oslo we decided to take the question of how to deal with
>>Mobile nodes that have a private IP address and obtain consensus on
>>the mailing list. The options at hand for which consensus from the WG
>>is sought in order to move forward, w.r.t handling private addresses
>>in Mobile IP are :
>>
>>1. Use co-located care of address as an option for mobile nodes with
>>   private addresses when they are roaming outside their
>>   administrative domains.
>>
>>2. Mandatory reverse tunnelling for mobile nodes that prefer to use
>>   the Foreign Agents Care Of Address but have a private address.
>>
>>3. The WG will develop a new solution to deal with the problem of
>>   private address spaces for Mobile IP.
>>
>
>Hello,
>
>Based on the feedback received from the Working Group members, we have
>a rough consensus for option 2.
>
>Option 1 is also feasible and hence should be considered as a
>possibility (depending on the MN capabilities).
>
>The conclusion from this exercise is that Mobile nodes which have
>a private IP address or belong in a domain that has private IP
>addresses can work with option 2 or 1. With the near term goal being
>focused on deployment issues, the WG will accept these options (2 and 1) as
>a solution to this problem as we move forward.
>More elegant or elaborate solutions to address the problem can be
>studied by the WG over the long term.
>
>Basavaraj Patil
>Phil Roberts

---

From: Tom Hiller <[email-masked]>
Date: Mon, 15 Nov 1999 16:18:36 -0600

Hi everyone -

I think a section in RFC 2344 as Gariel suggests makes sense because private
address support is naturally related to reverse tunneling.

Also, layer 2 protocols in other access technologies is able to provide
disambiguation and security, such as ADSL and cable modem.  So this private
address feature isn't inherently cellular only.

Tom