Subject: RE: [Mip6] How to store DNS records about HAs, (draft-ietf-mip6-bootstrapping-split-02.txt)?

From: "COMBES Jean-Michel RD-MAPS-ISS" <[email-masked]>
Date: Tue, 2 May 2006 18:34:40 +0200

> -----Original Message-----
> From: Alexandru Petrescu [mailto:[email-masked]] 
> Sent: Tuesday, May 02, 2006 2:02 PM
> To: Gerardo Giaretta
> Cc: Chowdhury, Kuntal; [email-masked]; COMBES Jean-Michel RD-MAPS-ISS
> Subject: Re: [Mip6] How to store DNS records about HAs, 
> (draft-ietf-mip6-bootstrapping-split-02.txt)?
> 
>

[snip]
 
> Alex
> PS: I don't think there's a clearcut  difference between "HA 
> discovery"
> and "HA assignment".  DHAAD is mainly discovery but its 
> effect is that MN gets its HA address, thus it is assigned 
> the HA address.
> 

Alex,

When you book a room in a hotel, who does decide finally on the number
of your room? This is the hotel, regarding what type of room you want
and the ones that are available. This is assignment :)

Best regards.

JMC.

France Telecom - R&D Division - MAPS/NSS   
Jean-Michel COMBES, Internet/Intranet Security
E-Mail: [email-masked]
Phone: +33 (0)1 45 29 45 94
Fax: +33 (0)1 45 29 65 19
Mobile: +33 (0)6 07 29 30 16 

_______________________________________________
Mip6 mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/mip6

---

From: Alexandru Petrescu <[email-masked]>
Date: Tue, 02 May 2006 18:48:23 +0200

COMBES Jean-Michel RD-MAPS-ISS wrote:
>> Alex PS: I don't think there's a clearcut  difference between "HA 
>> discovery" and "HA assignment".  DHAAD is mainly discovery but its
>>  effect is that MN gets its HA address, thus it is assigned the HA
>> address.
>> 
> 
> Alex,
> 
> When you book a room in a hotel, who does decide finally on the
> number of your room? This is the hotel, regarding what type of room
> you want and the ones that are available. This is assignment :)

YEs, and this assignment does not guarantee forwarding of all my mail
arriving at my house in my home country to the room assigned by that
hotel.  (For that, I'll have to tell La Poste (USMail) my real house
address and the room number at that hotel).

I suppose I'm correct to understand that HA assignment will not offer
session continuity from the previously assigned HA/HoA.

Alex

---

From: "Gerardo Giaretta" <[email-masked]>
Date: Tue, 2 May 2006 18:51:38 +0200

> session continuity from the previously assigned HA/HoA.

This is not a goal for the bootstrapping work.

--Gerardo

---

From: Alexandru Petrescu <[email-masked]>
Date: Tue, 02 May 2006 19:00:02 +0200

Gerardo Giaretta wrote:
>>>> Alex PS: I don't think there's a clearcut  difference between 
>>>> "HA discovery" and "HA assignment".  DHAAD is mainly discovery 
>>>> but its effect is that MN gets its HA address, thus it is 
>>>> assigned the HA address.
>>>> 
>>> 
>>> Alex,
>>> 
>>> number of your room? This is the hotel, regarding what type of 
>>> room you want and the ones that are available. This is assignment
>>>  :)
>> 
>> YEs, and this assignment does not guarantee forwarding of all my 
>> mail arriving at my house in my home country to the room assigned 
>> by that hotel.  (For that, I'll have to tell La Poste (USMail) my 
>> real house address and the room number at that hotel).
>> 
>> I suppose I'm correct to understand that HA assignment will not 
>> offer session continuity from the previously assigned HA/HoA.
>> 
> 

I think bootstrapping that forces MN to change its HoA is not adequate
to the MIP6 goal of session continuity and reachability at a permanent
home address, over the world-wide Internet.

And if we assume that MN does not need session continuity then it is
sufficient for MN to just use DHCPv6 in the visited network, get a new
address each time.

I may be wrong though.

Alex

---

From: Vijay Devarapalli <[email-masked]>
Date: Tue, 02 May 2006 10:20:01 -0700

> session continuity from the previously assigned HA/HoA.

yes. MIP6 bootstrapping enables scenarios where the
IPv6 HoA is no longer the identity of the mobile
node. there is a separate identity and every time
the mobile node bootstraps it could get a new HoA
and HA.

Vijay

---

From: Alexandru Petrescu <[email-masked]>
Date: Tue, 02 May 2006 20:04:25 +0200

Vijay Devarapalli wrote:
> yes. MIP6 bootstrapping enables scenarios where the IPv6 HoA is no 
> longer the identity of the mobile node. there is a separate identity 
> and every time the mobile node bootstraps it could get a new HoA and 
> HA.

But applications use IPv6 addresses, not other separate identities.  If
I have an app that uses an id which is not the IPv6 address (i.e. a
skype id) then just use DHCPv6 not MIP6, no?

Alex

---

From: Vijay Devarapalli <[email-masked]>
Date: Tue, 02 May 2006 11:16:30 -0700

Alexandru Petrescu wrote:

>> and every time the mobile node bootstraps it could get a new HoA and HA.
> 

you can do that. but if you move and your IP
address changes changes while the skype session is
on, the session might break.

Alex, there are a fourth step described in the
bootstrapping documents. Dynamic DNS update for the
MN. by using that mechanism, the MN can ensure its
current HoA is always in the DNS entry. so even if
the HoA changes everytime the MN bootstraps, the MN
can at least ensure CNs get the right HoA when they
do a DNS lookup for the MN.

Vijay

---

From: Alexandru Petrescu <[email-masked]>
Date: Tue, 02 May 2006 20:59:40 +0200

Vijay Devarapalli wrote:
>>>> YEs, and this assignment does not guarantee forwarding of all 
>>>> my mail arriving at my house in my home country to the room 
>>>> assigned by that hotel.  (For that, I'll have to tell La Poste
>>>>  (USMail) my real house address and the room number at that 
>>>> hotel).
>>>> 
>>> yes. MIP6 bootstrapping enables scenarios where the IPv6 HoA is 
>>> no longer the identity of the mobile node. there is a separate 
>>> identity and every time the mobile node bootstraps it could get a
>>>  new HoA and HA.
>> 
>> But applications use IPv6 addresses, not other separate identities.
>>  If I have an app that uses an id which is not the IPv6 address 
>> (i.e. a skype id) then just use DHCPv6 not MIP6, no?
> 
> you can do that. but if you move and your IP address changes changes
>  while the skype session is on, the session might break.

Right, if the laptop's IP address changes (with DHCP, no MIP) its
ongoing sessions will break, I think it's the case with skype.  But when
acquiring a new address the laptop will be again reachable at same skype id.

> Alex, there are a fourth step described in the bootstrapping 
> documents. Dynamic DNS update for the MN. by using that mechanism, 
> the MN can ensure its current HoA is always in the DNS entry. so even
>  if the HoA changes everytime the MN bootstraps, the MN can at least
>  ensure CNs get the right HoA when they do a DNS lookup for the MN.

For DNS update to offer session continuity at a permanent fqdn, it's
assumed that apps will DNS resolve their peer's fqdn every time an
ongoing session breaks.  I think this behaviour is unusual.  At least we
can't plan to re-program all apps to do so.

What DNS update in the home network offers is reachability at a
permanent fqdn (just as skype offers permanent skype id, with DHCP); but
DNS update too might involve breaking the session continuity at same IP
address, no?

Alex