Subject: [nemo] Questions

From: "Ferial Mimoune" <[email-masked]>
Date: Wed, 9 Aug 2006 14:37:25 +0100

Hi,
I want to ask you some questions, if you want to answer me.
I wish a little more precision please.

1- the MR sends a RA to all the node in the mobile network,  where the
prefix is entirely different from the prefix obtained by the MR from
the AR, it obtains this prefix by mechanisms of delegation of prefix
such as Automatic Prefix Delegation,  Router Advertisement Prefix
Delegation or Is IPv6 Prefix Options for DHCPv6, is this that?
and this prefix could be derived from the prefix obtained by the MR in
the RA sent by the AR?

2- LFN (Local Fixed Node) in the mobile network, can configure a
 temporary  address but this address will not be register to another
node, can it use this address as IPv6 address when it is attached to a
mobile network and send packets with this address (its CoA) as source
address, will be  this possible?

Best regards,
Ferial

---

From: Alexandru Petrescu <[email-masked]>
Date: Thu, 10 Aug 2006 11:25:28 +0200

Ferial Mimoune wrote:
> Hi, I want to ask you some questions, if you want to answer me. I 
> wish a little more precision please.
> 
> 1- the MR sends a RA to all the node in the mobile network,  where 
> the prefix is entirely different from the prefix obtained by the MR 
> from the AR, it obtains this prefix by mechanisms of delegation of 
> prefix such as Automatic Prefix Delegation,  Router Advertisement 
> Prefix Delegation or Is IPv6 Prefix Options for DHCPv6, is this that?

Hi Ferial, thanks for the question, shorter phrases would be better :-)

Terminology: Automatic Prefix Delegation - what is it?  What draft/RFC?
              Router Advertisement Prefix Delegation - what is it?
              DHCPv6 Prefix Delegation - I know what is, it is specified
              in an RFC.

> and this prefix could be derived from the prefix obtained by the MR 
> in the RA sent by the AR?

Well, the prefix sent in an RA is usually for hosts to derive addresses
from it, not to be propagated further; thus, by current RFCs the prefix
received by a router (in RA) should not be used to derive another prefix
and re-propagate it further.

There are however some exceptions to this behaviour.  With Router
Renumbering (RFC2894) routers forward Commands amongst them, and the
Commands contain new prefixes to be used.  With HMIPv6 (RFC4140) a MAP
Option contained in one RA is propagated by all routers in a domain, in
subsequent RAs.

One could build a system where the MR derives a new prefix from the
prefix received in the RA on its egress interface.  For what purpose?

> node, can it use this address as IPv6 address when it is attached to 
> a mobile network and send packets with this address (its CoA) as 
> source address, will be  this possible?

Yes, it is possible for LFN to configure several IPv6 addresses on its
interface, and use any of these addresses as source address for some
communications.  If the address is derived from a prefix MR derived from
the prefix received in its egress interface, then this address will
change every time MR receives a new prefix in its egress interface.
That is LFN's address is not stable, i.e. its communications break when
MR changes prefix.

But as long as MR stays attached to the same wireless system and
receives the same prefix, LFN's address won't change.  If this
connection is long enough for user purpose then its communications won't
break.

Alex

---

From: Andy Huang <[email-masked]>
Date: Thu, 10 Aug 2006 18:36:49 +0800

----- Original Message ----- 
From: "Alexandru Petrescu" <[email-masked]>
To: "Ferial Mimoune" <[email-masked]>
Cc: <[email-masked]>
Sent: Thursday, August 10, 2006 5:25 PM
Subject: Re: [nemo] Questions

> Ferial Mimoune wrote:
>> Hi, I want to ask you some questions, if you want to answer me. I wish a 
>> little more precision please.
>>
>> prefix is entirely different from the prefix obtained by the MR from the 
>> AR, it obtains this prefix by mechanisms of delegation of prefix such as 
>> Automatic Prefix Delegation,  Router Advertisement Prefix Delegation or 
>> Is IPv6 Prefix Options for DHCPv6, is this that?
>

=> It may be useful to RO. There is an expired I-D using similar method to 
solve NEMO RO.

>> temporary  address but this address will not be register to another node, 
>> can it use this address as IPv6 address when it is attached to a mobile 
>> network and send packets with this address (its CoA) as source address, 
>> will be  this possible?
>

---

From: "Ferial Mimoune" <[email-masked]>
Date: Sat, 12 Aug 2006 14:04:15 +0100

Thank you alex for your answers and for your interest.
I want to speak about Route Optimization(RO) in mobile network which
allows each mobile nodes in mobile network to perform RO, the MR gets
a prefix from an AR using:
-Automatic Prefix Delegation:It allows routers to request any prefix
from the upper
router and defines two new ICMP message types.
-Router Advertisement Prefix Delegation: extends the functionality of
the IPv6 Router
Advertisement (RA) messages and it can be used to assign one or more
address prefixes
- and DHCPv6
Thereafter,the MR advertises the delegated prefix to its subnet by
sending a RA to all the nodes in mobile network to configure their
care-of addres.

Best regards,
Ferial.

---

From: "Ferial Mimoune" <[email-masked]>
Date: Sat, 12 Aug 2006 14:09:24 +0100

Thank you alex for your answers and for your interest.
I want to speak about Route Optimization(RO) in mobile network which
allows each mobile nodes in mobile network to perform RO, the MR gets
a prefix from an AR using:
-Automatic Prefix Delegation:It allows routers to request any prefix
from the upper router and defines two new ICMP message types.
-Router Advertisement Prefix Delegation: extends the functionality of
the IPv6 Router Advertisement (RA) messages and it can be used to
assign one or more address prefixes
- and DHCPv6
Thereafter,the MR advertises the delegated prefix to its subnet by
sending a RA to all the nodes in mobile network to configure their
care-of addres.

Best regards,

Ferial.