Subject: [MEXT] DSMIPv6 deregistration

From: Suresh Krishnan <[email-masked]>
Date: Wed, 25 Jun 2008 13:57:04 -0400

Hi Folks,
   When the MN de-registers using DSMIPv6 and it had an IPv4 address 
does it need to include the IPv4 Home Address Option in the BU with 
lifetime 0? If so, is this a SHOULD or a MUST?

Thanks
Suresh
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From: "Vijay Devarapalli" <[email-masked]>
Date: Wed, 25 Jun 2008 14:08:15 -0400

> -----Original Message-----
> From: [email-masked] [mailto:[email-masked]] On Behalf
Of
> Suresh Krishnan
> Sent: Wednesday, June 25, 2008 10:57 AM
> To: [email-masked]
> Subject: [MEXT] DSMIPv6 deregistration
> 
> Hi Folks,

The mobile node does not have to. Both bindings (for the IPv6 and IPv4
home addresses) are removed.

Vijay

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From: Hesham Soliman <[email-masked]>
Date: Thu, 26 Jun 2008 07:59:22 +1000

It's a MAY. Actually, if you're trying to save bits you should not include
the IPv4 addresses. If you de-register, you're removing all bindings.

I don't think the spec has keywords associated with this.

Hesham

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From: Sri Gundavelli <[email-masked]>
Date: Wed, 25 Jun 2008 15:05:13 -0700 (PDT)

> I don't think the spec has keywords associated with this.

What will be the key for the binding lookup ? If the
entries are kept seperate, is the v4 HoA not required ?

Sri

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From: "Vijay Devarapalli" <[email-masked]>
Date: Wed, 25 Jun 2008 18:59:48 -0400

> entries are kept seperate, is the v4 HoA not required ?

If you have two separate bindings, you need to link them in your
implementation. If the primary binding cache entry (I consider the one
for the IPv6 home address as the primary one) is removed, the IPv4 home
address binding cache entry should also be removed.

Currently we don't support a scenario where the mobile node can delete
the binding cache entry for the IPv6 home address, but keep the one for
the IPv4 home address.

Vijay

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From: Sri Gundavelli <[email-masked]>
Date: Wed, 25 Jun 2008 20:48:15 -0700 (PDT)

> address binding cache entry should also be removed.

If the draft has recommendation for seperate binding entries,
it would be good have the required identifier present and
avoid this special links between bindings. Changing that MAY
to MUST is better, saving those 4 bytes is not worth the special
linking logic. Why recommend seperate BCE's and why expect this
special linkage, if you consider all of them as one, just bundle
them in one.

> the binding cache entry for the IPv6 home address, but keep the one for

I thought selective dereg is possible. I'm not sure if the MN is
mandated to include HoA option(s) for all the currently obtained
IPv4 addresses/prefixes and if the HA is forced to return them
in dereg. Either way, bit more explicit language in 5.5 will help.

Sri

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From: Sri Gundavelli <[email-masked]>
Date: Wed, 25 Jun 2008 20:51:32 -0700 (PDT)

> in dereg. Either way, bit more explicit language in 5.5 will help.

In re-registrations I meant, if all obtained HoA's have to be
present ...,

Sri

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From: Hesham Soliman <[email-masked]>
Date: Thu, 26 Jun 2008 17:13:20 +1000

> If the draft has recommendation for seperate binding entries,

=> The draft has no such recommendation. There is only one logical binding
and that is tied to the IPv6 address.

> I thought selective dereg is possible.

=> No.

Hesham

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From: Hesham Soliman <[email-masked]>
Date: Thu, 26 Jun 2008 17:14:25 +1000

Sri, the draft explicitly states that the HAO is not used in the BU. Please
check the BU format used.

Hesham

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From: "Premec, Domagoj" <[email-masked]>
Date: Thu, 26 Jun 2008 16:13:35 +0200

If ARP is used on the IPv4 home link, are there any requirements on the MN and HA related to proxy/gratuitous ARP when the MN returns home?
domagoj

> From: [email-masked] [mailto:[email-masked]] On 
> Behalf Of Suresh Krishnan
> Sent: 25. lipanj 2008 19:57
> To: [email-masked]
>    When the MN de-registers using DSMIPv6 and it had an IPv4 
> address does it need to include the IPv4 Home Address Option 
> in the BU with lifetime 0? If so, is this a SHOULD or a MUST?
> 
> Thanks
> Suresh

---

From: Sri Gundavelli <[email-masked]>
Date: Thu, 26 Jun 2008 09:07:10 -0700 (PDT)

> => The draft has no such recommendation. There is only one logical
> binding and that is tied to the IPv6 address.
>

Ok. Fine. These two places on BCE and BUL entries, it suggested
multiple entries. May be you may want to be specific, since this
is one mobility session, its still one logical entry. However, I'd
prefer to keep all the state associated to a mobility session in
one BCE entry, just as how NEMO does.  This special BCE linking as
Vijay suggested is not implied, that needlessly changes the BCE
data structure implementation on existing HA's.

Sec 5.5, On BCE entries

      If the binding update is accepted for both IPv4 and IPv6 home
       addresses, the home agent creates separate binding cache entries,
       one for each home address.  The care-of address is the one
       included in the binding update.  If the care-of address is an IPv4
       address, the home agent MUST setup a tunnel to the IPv4 care-of
       address of the mobile node.

5.4: On BUL entries:
       If the mobility header includes an IPv4 address acknowledgement
       option indicating success, the mobile node should create two
       entries in its binding update list, one for the IPv6 home address
       and another for the IPv4 home address.

Thanks
Sri

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From: Sri Gundavelli <[email-masked]>
Date: Thu, 26 Jun 2008 09:20:24 -0700 (PDT)

Hi Hesham,

> check the BU format used.

I was referring to the IPv4 Home Address Option. Its is there in the
BU. Specific question, if the mobile needs to include IPv4 HoA option
for each of the currently assigned IPv4 home addresses or prefixes ?
>From the below text, its not clear if the MN should include IPv4 home
address option for each of the addresses. Also, I'm not sure if the
format for re-registration messages is the same as the initial message,
few lines will help. Or if it is there, if you can point me.

5.4: MN Operation:

    When sending a binding update from a visited network that supports
    IPv6, the mobile node MUST follow the rules specified in [RFC3775].
    In addition, if the mobile node has an IPv4 home address or needs
    one, it MUST include the IPv4 home address option in the mobility
    header.  If the mobile node already has a static IPv4 home address,
    this address MUST be included in the IPv4 home address option.
    Otherwise, if the mobile node needs a dynamic IPv4 address, it MUST
    include the IPv4 0.0.0.0 address in the IPv4 home address option.

Thanks
Sri

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From: Hesham Soliman <[email-masked]>
Date: Fri, 27 Jun 2008 10:49:31 +1000

Sri,

> for each of the currently assigned IPv4 home addresses or prefixes ?

=> Yes. 

  Also, I'm not sure if the
> few lines will help. Or if it is there, if you can point me.

=> I don't think there is anything in the spec about that. The BU, as
defined in 3775 is always the same format, there is no distinction between
the format for initial and refresh AFAIK. We don't need to talk about that
because you only talk about something when you've deviated from the
well-known norm. Otherwise, we would have to repeat major sections of 3775.

Hesham

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From: Sri Gundavelli <[email-masked]>
Date: Thu, 26 Jun 2008 18:05:44 -0700 (PDT)

Hesham,

> well-known norm. Otherwise, we would have to repeat major sections of 3775.

Sorry, I was not clear. When I say format, I meant if all the IPv4 HoA
options should be present and if the values should reflect the assigned
values or if the PBU can just be the initial PBU and potentially with
the option values of 0.0.0.0.

Fine, if you think this is implied.

Sri