Subject: [mobile-ip] Contradicting FA behaviors in RFC3344

From: "Zeng, Iris [NTWK SVCS]" <[email-masked]>
Date: Wed, 4 Jun 2003 11:31:34 -0500

Charlie, and all,
In RFC3344, there is a conflict on FA's behavior towards invalid RRQ. In section 3.7.2, it says if the FA denies the RRQ, it MUST send a RRP to the MN. But in Section 3.7.2.3 (and as well as other sections), it says if the FA denies the RRQ for any reason, it SHOULD send the MN a RRP. The texts are copies as below.

Suggestion: Change the "MUST" in section 3.7.2 to "SHOULD". In the other words, allow the FA take 1 of the following 3 actions, if it denies the RRQ: Sending a RRP to the MN (recommended by using wording "SHOULD"), Not sending a RRP to the MN, or silently discarding the RRQ.

Let me know what you think,
Thanks,
Iris Zeng

In section 3.7.2, "Receiving Registration Request", the first paragraph,

"If the foreign agent accepts a Registration Request from a mobile
   node, it checks to make sure that the indicated home agent address
   does not belong to any network interface of the foreign agent.  If
   not, the foreign agent then MUST relay the Request to the indicated
   home agent.  Otherwise, if the foreign agent denies the Request, it
   MUST send a Registration Reply to the mobile node with an appropriate
   denial Code, except in cases where the foreign agent would be
   required to send out more than one such denial per second to the same
   mobile node.  The following sections describe this behavior in more
   detail."

But in section 3.7.2.3 "Denying Invalid Requests", the first 2 paragraphs,

"If the foreign agent denies the mobile node's Registration Request
   for any reason, it SHOULD send the mobile node a Registration Reply
   with a suitable denial Code.  In such a case, the Home Address, Home
   Agent, and Identification fields within the Registration Reply are
   copied from the corresponding fields of the Registration Request.

   If the Reserved field is nonzero, the foreign agent MUST deny the
   Request and SHOULD return a Registration Reply with status code 70 to
   the mobile node.  If the Request is being denied because the
   requested Lifetime is too long, the foreign agent sets the Lifetime
   in the Reply to the maximum Lifetime value it is willing to accept in
   any Registration Request, and sets the Code field to 69.  Otherwise,
   the Lifetime SHOULD be copied from the Lifetime field in the Request."