Subject: [dhcwg] A problem of unicasting Solicit message

From: "haoda" <[email-masked]>
Date: Tue, 20 Dec 2005 19:05:01 +0900

Hi!

I have a problem of RFC3315.
It is about the using with unicast address in Solicit message.

At "15. Message Validation",(P27, line 1506)
RFC said like this,
"  A server MUST discard any Solicit, Confirm, Rebind or
   Information-request messages it receives with a unicast destination
   address."
My understanding is the server must discard the Solicit message
via unicast.

But at the other place, "17.2.2 " (P37, line 2058)
there is differrent description.
"   If the Solicit message was received directly by the server, the
   server unicasts the Advertise message directly to the client using
   the address in the source address field from the IP datagram in which
   the Solicit message was received.  The Advertise message MUST be
   unicast on the link from which the Solicit message was received."
This pragraph tells me that the server need send Advertise message
via unicast when receiving a uncasting Solicit message.

It looks not consitent,isn't it? 
Please tell me how to understand the 2 ones.

Regard yours,
Haoda

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

---

From: JINMEI Tatuya / 神明達哉<[email-masked]>
Date: Wed, 21 Dec 2005 15:10:16 +0900

>>>>> On Tue, 20 Dec 2005 19:05:01 +0900, 
>>>>> "haoda" <[email-masked]> said:

> It looks not consitent,isn't it? 

My interpretation of "received directly by the server" is that it is
not forwarded by a relay agent, rather than being unicasted by a
client.  In fact, the succeeding paragraph of the cited part mentions
the case where the SOLICIT is forwarded:

   If the Solicit message was received in a Relay-forward message, the
   server constructs a Relay-reply message with the Advertise message in
   the payload of a "relay-message" option.  If the Relay-forward
   messages included an Interface-id option, the server copies that
   option to the Relay-reply message.  The server unicasts the
   Relay-reply message directly to the relay agent using the address in
   the source address field from the IP datagram in which the Relay-
   forward message was received.

So I don't think the two text fragments you cited are inconsistent
(actually they are irrelevant).

					JINMEI, Tatuya
					Communication Platform Lab.
					Corporate R&D Center, Toshiba Corp.
					[email-masked]

---

From: "haoda" <[email-masked]>
Date: Tue, 27 Dec 2005 10:39:30 +0900

Hi, Mr. Jinmei,

Thanks for your reply.

> the case where the SOLICIT is forwarded:

I think your interpertation of "received directly by the server" is the
Solicit message is sent by the client like the common way. That is,
multicast it from the client to the server. 
This pragraph only want to tell us the return message of server must
be transimit via unicast in the common case.

Is my understanding same as your interpretation?

Sincerely yours,
Haoda