Subject: [shara] Follow up on Layer2-Aware NAT (draft-miles-behave-l2nat-00)

From: <[email-masked]>
Date: Thu, 26 Mar 2009 14:16:56 +0100

The comment I had on the mike during behave session 2:

This kind of work is very valuable, it is worth not only for CGN but
also for Port Ranges solutions and for all IPv4 shortage solutions. 
As we presented it in the shara BoF all solutions basically:
1) Put a dedicated function in an ISP Box (CGN, PRR, whatever)
2) Use some sort of transport mechanism (tunneling, layer 2, whatever)
between customers and ISPBox, 
3) Are confronted with the same issues: how to force a route from
customers to ISPBox, how to route back from ISPBox to relevant customer,
how to identify the customer. 

This would advocate for seeing all work related to IPv4 shared addresses
host in the same place, under the same ombrella.

Regards

Pierre

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From: "MILES DAVID" <[email-masked]>
Date: Sat, 28 Mar 2009 08:27:08 +0800

Pierre,

Thanks for the support. The presentation of draft-nishitani-cgn-01
outlined a good way forward - here the Network Model was separated from
the core NAT Function. I think a L2-Aware NAT best belongs in a core
document like this.
In this way L2-Aware NAT could make up an optional component of the core
NAT Function (in the way it describes a Virtual NAT [tables] facility).
On top of this a variety of network models could be created and
documented - these could even come from other working groups (such as
Softwires).I believe a core NAT function (regardless of whether we
describe IPv4 or IPv6) fits well in BEHAVE. 

Applying the mechanisms in L2-Aware NAT to PRR makes a lot of sense as
well - I'm wondering if port-range solutions could be described (perhaps
poorly) as similar to a NAPT mapping function (outside-ip/port to
inside-ip/port) however in the case of PRR, the pairs are the
same/common - in effect a address/port translation does not occur. What
do you think of attempting to describe the PRR function like this?

If agreeable I would like to invite the authors of PRR/A+P and CGN
drafts to work within the bounds of a new draft that describes a core
NAT function (without drawing reference to size or scale) - introducing
elements of core NAT function (CGN/LSN) virtual NAPT tables (L2-Aware
NAT), and mappings tables where translation is not applied (PRR).

Best Regards,

-David

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf
Of [email-masked]
Sent: Thursday, March 26, 2009 6:17 AM
To: [email-masked]; [email-masked]
Subject: [shara] Follow up on Layer2-Aware NAT
(draft-miles-behave-l2nat-00)

Regards

Pierre
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From: Randy Bush <[email-masked]>
Date: Sat, 28 Mar 2009 14:53:08 -0700

> NAT), and mappings tables where translation is not applied (PRR).

hmmmm.  have you read the latest a+p i-d?

randy

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From: "Gabor Bajko" <[email-masked]>
Date: Sun, 29 Mar 2009 11:02:16 -0700

There were a number of inconsistencies on the comparison slide (eg, that
IPv4 traffic is subject to NAPT in case of A+P, etc). 

It has to be clearly stated that what this solution offers is a
technological dead-end, as there is no evolution path away from IPv4 in it. 

- gabor

  >From: [email-masked] [mailto:[email-masked]] On Behalf
  >Of MILES DAVID
  >Sent: Friday, March 27, 2009 5:27 PM
  >To: [email-masked]; [email-masked]; [email-masked]
  >Subject: Re: [BEHAVE] [shara] Follow up on Layer2-Aware NAT(draft-miles-
  >behave-l2nat-00)
  >
  >Pierre,
  >
  >Behave mailing list
  >[email-masked]
  >https://www.ietf.org/mailman/listinfo/behave

---

From: "MILES DAVID" <[email-masked]>
Date: Tue, 31 Mar 2009 12:20:21 +0800

Hi Gabor,

I understand that the last slide was far too generalized. 

All transition solutions will involve a degree of IPv4 if they involve a
v4 client - in L2-Aware NAT there is a component of IPv4 NAPT but this
does not preclude the approach from using IPv4-in-IPv6 tunneling
solutions.

You'll get no objection from me that IPv4 is a dead-end - what we are
trying to do is provide -minimal- support for IPv4 during the transition
period to IPv6.

Cheers,

-David

-----Original Message-----
From: Gabor Bajko [mailto:[email-masked]] 
Sent: Monday, March 30, 2009 5:02 AM
To: MILES DAVID; [email-masked]; [email-masked];
[email-masked]
Subject: RE: [BEHAVE] [shara] Follow up on Layer2-Aware
NAT(draft-miles-behave-l2nat-00)

It has to be clearly stated that what this solution offers is a
technological dead-end, as there is no evolution path away from IPv4 in
it. 

- gabor