Subject: [Mip4] dynamic assignment

From: "Jeremy A. Greene" <[email-masked]>
Date: Wed, 4 Feb 2004 15:13:13 -0500

>From draft-ietf-mip4-dynamic-assignment-00.txt, I have a few questions.

1.    Does the Requested HA do full auth or not? And if so, can/does the
redirected HA (and ultimately Assigned HA) also do auth?

a.    Could permit separating the 'signaling' path from the data path.

2.    The text below seems to be incorrect? The initial RRQ can be a
subnet bcast? I gather this is referring to the bcast always being
rejected w/ the ha addr field set to a unicast ha addr?

        6. Requested Home Agent Selection 
           The destination IP address of the first Registration Request
in 
        the Mobile IP session is the Requested HA.  This address MUST 
        be a unicast IP address.  

3.    Below, the red text seems unnecessary since it's a unicast?

        No. Dest IP Addr  HA field     Processing at Assigned HA 

        --  ------------  ------------ ------------------------- 

        1   Unicast       Unicast      RFC 3344: Normal HA processing 

                          Same as Dest per RFC 3344. 

                          IP addr       

                          Unicast      RFC   3344:   HA   denies   the 

                          Different    registration  with  error  code 

                          than Dest IP 136 and sets HA field to its 

                          Addr         own IP address in the reply as 

                                       per section 3.8.3.2. 

                                                     OR 

                                        New    Behavior:    Dest    IP 

                                        corresponds to the HA receiving 

                                        RRQ,   if   authentication   is 

                                        successful, reject RRQ with a 

                                        new  error  code  (REDIRECT-HA-

                                        REQ). HA puts its address in HA 

                                        address  field  of  Reject.  HA 

                                        suggests an alternate HA to use 

                                        in   the   new   REDIRECTED-HA-

                                        ADDRESS extension.

Jeremy

---

From: Kent Leung <[email-masked]>
Date: Wed, 04 Feb 2004 17:20:01 -0800

Hi Jeremy.  Thanks for your feedback.  Comments below.

At 03:13 PM 2/4/2004 -0500, Jeremy A. Greene wrote:

>a.    Could permit separating the signaling path from the data path.

The HA that processes the RRQ does the authentication.  For example, MN 
sends RRQ to HA1.
HA1 authenticates RRQ and sends rejected RRP with alternative HA2.  MN 
sends RRQ to HA2.
HA2 authenticates RRQ and sends accepted RRP.

>            The destination IP address of the first Registration Request in

The reason that this address should not be subnet directed broadcast address is
CERT Advisory CA-1998-01 as mentioned in the spec.

Maybe we should change this to "This address SHOULD be a unicast IP address".

>3.    Below, the red text seems unnecessary since it s a unicast?
>

So you're saying that this is implicit?  The HA would not have received the
RRQ if the destination IP address did not belong to that HA.

Maybe better wording is "IP address in HA field is not HA's, ... reject ..."?

Kent