Subject: [nemo] RE: Home Network models update

From: "Pascal Thubert \(pthubert\)" <[email-masked]>
Date: Thu, 19 Jan 2006 11:22:51 +0100

Hi Pekka:

The Cab Co illustration is a bit hard to follow. Using cab:co::/32
actually helped people and I got positive comments on that in the past.
I added the following sentence just above the drawing:

  "To illustrate this configuration, we make up the prefixes to reflect
   their role, like CAB:C0::/32 for the Home Network:"

So section 8 looks like this now:

   8.1  Configuration

   In this arrangement, there is a bitwise hierarchy of Home Networks.
   A global Home Network is advertised to the infrastructure by a head
   Home Agent(s) and further subnetted into Mobile Networks.  As a
   result, only the Home Agent(s) responsible for the most global
   (shortest prefix) aggregation receive all the packets for all the
   MNPs, which are leaves in the hierarchy tree.

   Each subnet is owned by a Mobile Router that registers it in a NEMO
   fashion while acting as a Home Agent for that network This Mobile
   Router is at Home at the upper level of hierarchy.  This
   configuration is referred to as Mobile Home.

   An example of this is the Cab Co configuration.  Cab Co is a taxi
   Company that uses a /32 prefix for its Home Network, this prefix
   being advertised by the company Head Quarters.  Regional offices are
   deployed around the coutry.  Even though these regional offices are
   relatively stable in terms of location and prefix requirement -say
   this changes every few years- making them mobile allows a simpler
   management when a move has to take place, or should the ISP service
   change.

   To illustrate this configuration, we make up the prefixes to reflect
   their role, like CAB:C0::/32 for the Home Network:

         global Home Network   CAB:C0::/32  advertised by HQ
    <------------------------------------------------------------------>

      HQ Extended Home Net              Mobile Home for SFO office
          (casa)
      CAB:C0:CA5A::/48                          CAB:C0:5F0::/48
    <----------------------------> ... <------------------------------->
                                                       |
      Home for offices        HQ                       |
     CAB:C0:CA5A:CA5A::/64    MN                       |
    <----------------------><---->                     |
     CAB:C0:CA5A:CA5A::CA5A                            |
     CAB:C0:CA5A:CA5A::CA5B                            |
     are HAs on link with for each office a route like |
                                                       |
     CAB:C0:CA5A:CA5A::5F0    <---------------------- via
       is the Home addr
       of SFO office

                  Figure 6:  CAB Company HQ configuration

Is that OK with you?

Pascal

>-----Original Message-----
>From: Pekka Savola [mailto:[email-masked]]
>Sent: Tuesday, January 17, 2006 11:15 AM
>To: Pascal Thubert (pthubert)
>Cc: [email-masked]; Margaret Wasserman
>Subject: Re: Home Network models update
>
>On Tue, 17 Jan 2006, Pascal Thubert (pthubert) wrote:
>> editorial
>> ---------
>>
>> ==> examples used the prefixes A:B:C::/48 and CAB:C0::/32.  You
should use 2001:db8::/32 instead as
>> it's specifically meant as a doc prefix -- unless you have strong
reasons for otherwise.
>>
>> Pascal: it was supposed to help the user understand it's Cab Co. Is
that a big problem?
>
>The document needs to justify why it uses those if that's what you
>wish to do.
>
>In this particular case, I see the "CAB:C0::/32" prefix used only
>under section 8, where you don't use any other prefixes, so I
>think using 2001:DB8::/32 shouldn't cause confusion here.
>
>--
>Pekka Savola                 "You each name yourselves king, yet the
>Netcore Oy                    kingdom bleeds."
>Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings

---

From: Pekka Savola <[email-masked]>
Date: Thu, 19 Jan 2006 14:11:51 +0200 (EET)

>   their role, like CAB:C0::/32 for the Home Network:"
...
> Is that OK with you?

OK.

---

From: Alexandru Petrescu <[email-masked]>
Date: Thu, 19 Jan 2006 15:50:53 +0100

Pekka Savola wrote:
>> "To illustrate this configuration, we make up the prefixes to
>> reflect their role, like CAB:C0::/32 for the Home Network:"
> ...
>> Is that OK with you?
> 
> OK.

Sorry for interfering.  I don't see why using Cab C0 instead of the
recommended 2001:db8::/32.

For one, Cab Co is easily confusable with Cab C0, because barred 0 looks
so only with _some_ fonts.

Fun hexa IPv6 prefixes exist all over the place in many other documents.
  DEAD::BEEF is another example.

During the lifetime of an RFC it may be the case that both DEAD::BEEF
and CAB::C0 will be allocated to some real deployments, at which point
reading that RFC may be confusing.  Is this RFC talking about _my_
deployment?

Alex

---

From: Alexandru Petrescu <[email-masked]>
Date: Thu, 19 Jan 2006 15:59:01 +0100

Pekka Savola wrote:
> -- Pekka Savola                 "You each name yourselves king, yet
> the Netcore Oy                    kingdom bleeds." Systems. Networks.
> Security. -- George R.R. Martin: A Clash of Kings
> 

Otherwise maybe make example 2001:DB8:cabc:0::/56 and then refer it into
the text as "the Cab Co prefix"?

Alex

---

From: Pekka Savola <[email-masked]>
Date: Fri, 20 Jan 2006 14:42:10 +0200 (EET)

> the text as "the Cab Co prefix"?

Let me expand on my feelings on this.

ID-Checklist makes it quite clear that other than 2001:DB8::/32 should 
not be used.  But that is just a guideline, and there have been cases 
in the past (I've written one myself: see RFC 3964) where it has been 
reasonable to use other prefixes instead.

In such cases, documenting the justification (and placing a warning) 
has been required.

Personally, I'm not really convinced that using CAB:C0::/32 brings 
enough value (I don't think it can be confused because it's only used 
in one section of the document, and other prefixes aren't mentioned in 
that part of the document).  But given that I don't think this issue 
is major and at least some reason has been proposed, I think this 
issue should be decided by the WG and the AD (Margaret).