Subject: [dhcwg] RFC 3315 clarification

From: ravi kumar <[email-masked]>
Date: Mon, 2 Nov 2009 16:30:08 +0530

I need clarification regarding section 18.1.8 of RFC- 3315 :

<Copy-paste from RFC>
When the client receives a Reply message in response to a Renew or
   Rebind message, the client examines each IA independently.  For each
   IA in the original Renew or Rebind message, the client:

   -  sends a Request message if the IA contained a Status Code option
      with the NoBinding status (and does not send any additional
      Renew/Rebind messages)

   -  sends a Renew/Rebind if the IA is not in the Reply message

   -  otherwise accepts the information in the IA

What is the intent of client for sending Request, in response to Sever's
reply with NOBINDING status code. What addresses do Request message contain
?
Incase of Client's message containing only one IA, Is it not enough that
Client starts with Solicit, instead o Request message.
Because, incase Client sends Request, then Server would either respond with
a Reply containing different Address (than requested) / ignores Client's
message, since address is not available with Server. In that case, client
finally falls back to Solicit to acquire address.
Instead if Client sends Solicit in response to Server's reply would quicken
address acquisition.
Please clarify me in this regard

regards
Ravi

---

From: "Bernie Volz (volz)" <[email-masked]>
Date: Mon, 2 Nov 2009 07:29:52 -0600

The reason is that the client is already using the server and the server
is up and running and a REQUEST is the only message that can create a
new binding.

While the client COULD return to SOLICIT, that requires more time and
processing than sending a REQUEST does. (It gets more complicated too if
the client has multiple bindings since it could end up communicating
with multiple servers for different bindings which is probably not as
desirable.)

The client is best to include the addresses it thinks it has in the
REQUEST - the server may or may not assign them to the client (it will
depend on what is in the REPLY). If the client does not include those
addresses, it would be unlikely to get them (as the server has no record
of them!) and that may cause problems because now the client may
continue to use those addresses until the valid lifetime expires but the
server has no record of those addresses being used (which means they
could end up being allocated to another client).

This case is really when the server has lost information on the
bindings.

-          Bernie

From: [email-masked] [mailto:[email-masked]] On Behalf
Of ravi kumar
Sent: Monday, November 02, 2009 6:00 AM
To: DHC WG
Subject: [dhcwg] RFC 3315 clarification

<Copy-paste from RFC>

What is the intent of client for sending Request, in response to Sever's
reply with NOBINDING status code. What addresses do Request message
contain ?

Because, incase Client sends Request, then Server would either respond
with a Reply containing different Address (than requested) / ignores
Client's message, since address is not available with Server. In that
case, client finally falls back to Solicit to acquire address.

Instead if Client sends Solicit in response to Server's reply would
quicken address acquisition.

regards

Ravi

---

From: ravi kumar <[email-masked]>
Date: Tue, 3 Nov 2009 17:46:02 +0530

Can you please explain more on below statement of yours  -
"It gets more complicated too if the client has multiple bindings since it
could end up communicating with multiple servers for different bindings
which is probably not as desirable."

>From RFC, Request message is sent only for those IA's that contains
NOBINDING status in Reply of Server. The above scenario would occur only
when  NOBINDING status received as part of multiple IA's. Is such situation
possible incase of Renew-Reply ? Please clarify!

<More Replies Inline>

regards
Ravi
On Mon, Nov 2, 2009 at 6:59 PM, Bernie Volz (volz) <[email-masked]> wrote:

> is up and running and a REQUEST is the only message that can create a new
> binding.
>
>
>
> processing than sending a REQUEST does. (It gets more complicated too if the
> client has multiple bindings since it could end up communicating with
> multiple servers for different bindings which is probably not as desirable.)
>
>  <Ravi> In specific case of  Client message containing only one IA with a
> single address, Is it not enough that Client starts with Solicit, instead o
> Request message ?
> message, since binding is not available with Server. Instead if Client sends
> Solicit in response to Server's reply would quicken address acquisition.
>
> The client is best to include the addresses it thinks it has in the REQUEST
> – the server may or may not assign them to the client (it will depend on
> what is in the REPLY). If the client does not include those addresses, it
> would be unlikely to get them (as the server has no record of them!) and
> that may cause problems because now the client may continue to use those
> addresses until the valid lifetime expires but the server has no record of
> those addresses being used (which means they could end up being allocated to
> another client).
>
>
>
> This case is really when the server has lost information on the bindings.
>
>
>
> -          Bernie
>
>
>
> *From:* [email-masked] [mailto:[email-masked]] *On Behalf
> Of *ravi kumar
> *Sent:* Monday, November 02, 2009 6:00 AM
> *To:* DHC WG
> *Subject:* [dhcwg] RFC 3315 clarification
>
>
>

---

From: "Bernie Volz (volz)" <[email-masked]>
Date: Tue, 3 Nov 2009 08:43:04 -0600

That statement was about if the client transitioned to SOLICIT state for
those bindings that returned NOBINDING status in the RENEW/REBIND. This
would then potentially result in the client selecting a DIFFERENT server
than it was using for existing bindings for which no issue existed (they
renewed).

Just follow the procedures in the RFC.

-          Bernie

From: ravi kumar [mailto:[email-masked]] 
Sent: Tuesday, November 03, 2009 7:16 AM
To: Bernie Volz (volz)
Cc: DHC WG
Subject: Re: [dhcwg] RFC 3315 clarification

"It gets more complicated too if the client has multiple bindings since
it could end up communicating with multiple servers for different
bindings which is probably not as desirable."

NOBINDING status in Reply of Server. The above scenario would occur only
when  NOBINDING status received as part of multiple IA's. Is such
situation possible incase of Renew-Reply ? Please clarify!

<More Replies Inline>

regards

Ravi

On Mon, Nov 2, 2009 at 6:59 PM, Bernie Volz (volz) <[email-masked]>
wrote:

 <Ravi> In specific case of  Client message containing only one IA with
a single address, Is it not enough that Client starts with Solicit,
instead o Request message ?
Because, incase Client sends Request, then Server would either respond
with a Reply containing different Address (than requested) / ignores
Client's message, since binding is not available with Server. Instead if
Client sends Solicit in response to Server's reply would quicken address
acquisition.

-          Bernie

<Copy-paste from RFC>

regards

Ravi