Subject: Re: [pcp] #34: notify NAT WAN address changed

From: "pcp issue tracker" <[email-masked]>
Date: Tue, 25 Feb 2014 02:59:07 -0000

#34: notify NAT WAN address changed

Changes (by [email-masked]):

 * status:  new => closed
 * resolution:   => fixed

Comment:

 This was addressed in RFC 6887.  Section 14.2 begins:
 > 14.2.  PCP Mapping Update
 >
 >   This rapid recovery mechanism is used when the PCP server remembers
 >   its state and determines its existing mappings are invalid (e.g., IP
 >   renumbering changes the external IP address of a PCP-controlled NAT).

-- 
--------------------------------------------------+---------------------
 Reporter:  [email-masked]  |       Owner:
     Type:  enhancement                           |      Status:  closed
 Priority:  minor                                 |   Milestone:
Component:  Extensions                            |     Version:
 Severity:  -                                     |  Resolution:  fixed
 Keywords:                                        |
--------------------------------------------------+---------------------

Ticket URL: <http://trac.tools.ietf.org/wg/pcp/trac/ticket/34#comment:4>
pcp <http://tools.ietf.org/pcp/>

---

From: <[email-masked]>
Date: Wed, 26 Feb 2014 10:11:18 +0100

Hi Dave, all,

I agree most of the issues captured in this ticket are solved, but still there is one remaining issue. 

As a reminder, the ticket refers to this text:

======
2.5. Change of the CPE WAN IP Address

   The change of the IP address of the WAN interface of the CPE would
   have an impact on the accuracy of the mappings instantiated in the
   PCP Server:

   o  For the DS-Lite case [I-D.ietf-softwire-dual-stack-lite]: if a new
      IPv6 address is used by the B4 element when encapsulating IPv4
      packets in IPv6 ones, the mappings SHOULD be refreshed: If the PCP
      Client is embedded in the B4, the refresh operation is triggered
      by the change of the B4 IPv6 address.  This would be more
      complicated when the PCP Client is located in a device behind the
      B4.

         [Ed.  Note: how an IPv4 host behind a DS-Lite CPE is aware that
         a new IPv6 address is used by the B4?]

   o  For the NAT64 case [I-D.ietf-behave-v6v4-xlate-stateful], any
      change of the assigned IPv6 prefix delegated to the CPE will be
      detected by the PCP Client (because this leads to the allocation
      of a new IPv6 address).  The PCP Client has to undertake the
      operation described in Section 2.4.
========

An issue is still unsolved in the DS-Lite case where the PCP client is not co-located with B4. This issue is not solved in the base PCP spec, but is addressed in this individual draft: http://tools.ietf.org/search/draft-vinapamula-softwire-dslite-prefix-binding-01 

The recommendation in http://tools.ietf.org/search/draft-vinapamula-softwire-dslite-prefix-binding-01 covers the PCP case, in particular these two recommendations:

   3.  In the event a new IPv6 address is assigned to B4, the AFTR
       SHOULD migrate existing state to be bound to the new B4's IP
       address.  This ensures the traffic destined to the previous IPv6
       address will redirected to the new IPv6 address.  The destination
       address for tunneling return traffic SHOULD be the last seen
       address from the CPE.  The source address of the tunnel would
       remain same as AFTR.

   4.  In the event of change of the CPE WAN IPv6 prefix, unsolicited
       PCP ANNOUNCE messages SHOULD be sent by the B4 element to
       internal hosts to update their mappings.

Cheers,
Med

>-----Message d'origine-----
>De : pcp [mailto:[email-masked]] De la part de pcp issue tracker
>Envoyé : mardi 25 février 2014 03:59
>À : [email-masked]; [email-masked]
>Cc : [email-masked]
>Objet : Re: [pcp] #34: notify NAT WAN address changed
>
>_______________________________________________
>pcp mailing list
>[email-masked]
>https://www.ietf.org/mailman/listinfo/pcp

---

From: Suresh Kumar Vinapamula Venkata <[email-masked]>
Date: Thu, 27 Feb 2014 20:18:08 +0000

Hi Dave, 

Section 14.2 of RFC6887 addresses change in external IP address of PCP
controlled NAT, and it doesn¹t address change in CPE WAN IP address. This
draft is addressing the change in CPE WAN IP address and suggests
recommendations. 

Thanks
Suresh

On 2/26/14 1:11 AM, "[email-masked]"
<[email-masked]> wrote:

>An issue is still unsolved in the DS-Lite case where the PCP client is
>not co-located with B4. This issue is not solved in the base PCP spec,
>but is addressed in this individual draft:
>http://tools.ietf.org/search/draft-vinapamula-softwire-dslite-prefix-bindi
>ng-01 
>
>The recommendation in
>http://tools.ietf.org/search/draft-vinapamula-softwire-dslite-prefix-bindi
>ng-01 covers the PCP case, in particular these two recommendations:
>

---

From: Dave Thaler <[email-masked]>
Date: Thu, 27 Feb 2014 22:40:53 +0000

I don't follow.  If the PCP server controls the NAT in the CPE, 
then the CPE WAN IP address *is* the external IP address of 
the PCP controlled NAT.

-Dave

> -----Original Message-----
> From: Suresh Kumar Vinapamula Venkata [mailto:[email-masked]]
> Sent: Thursday, February 27, 2014 12:18 PM
> To: [email-masked]; pcp issue tracker; [email-masked];
> Dave Thaler
> Cc: [email-masked]
> Subject: Re: [pcp] #34: notify NAT WAN address changed
> 
> Hi Dave,
> 
> >>Envoyé : mardi 25 février 2014 03:59 À : [email-masked];
> >>[email-masked] Cc : [email-masked] Objet : Re: [pcp] #34: notify
> >>NAT WAN address changed
> >>
> >>--------------------------------------------------+-------------------
> >>--------------------------------------------------+--
> >>--------------------------------------------------+-------------------
> >>--------------------------------------------------+--
> >>
> >>Ticket URL:
> >><http://trac.tools.ietf.org/wg/pcp/trac/ticket/34#comment:4>

---

From: Dave Thaler <[email-masked]>
Date: Thu, 27 Feb 2014 22:42:49 +0000

The DSlite case needs to be treated as a separate issue because it's
a separate doc.   I'll open a separate ticket to track that.

-Dave

> From: [email-masked]
> [mailto:[email-masked]]
> Sent: Wednesday, February 26, 2014 1:11 AM
> To: pcp issue tracker; [email-masked]; Dave Thaler
> Cc: [email-masked]; Suresh Kumar Vinapamula Venkata
> Subject: RE: [pcp] #34: notify NAT WAN address changed
> 
> Hi Dave, all,
> 
> An issue is still unsolved in the DS-Lite case where the PCP client is not co-
> located with B4. This issue is not solved in the base PCP spec, but is
> addressed in this individual draft: http://tools.ietf.org/search/draft-
> vinapamula-softwire-dslite-prefix-binding-01
> 
> The recommendation in http://tools.ietf.org/search/draft-vinapamula-
> softwire-dslite-prefix-binding-01 covers the PCP case, in particular these two
> recommendations:
> 
> >--------------------------------------------------+--------------------
> >--------------------------------------------------+-
> >--------------------------------------------------+--------------------
> >--------------------------------------------------+-
> >
> >Ticket URL:

---

From: Suresh Kumar Vinapamula Venkata <[email-masked]>
Date: Fri, 28 Feb 2014 00:32:50 +0000

Hi Dave, 

I was talking in the context of DS-Lite, what I meant by CPE WAN IP is the
B4 address of the CPE. Change of that address could result in inaccuracy
of that existing mappings of both PCP and non PCP. This draft is
addressing those issues. May be "IP" address, might have confused you.

-Suresh