Subject: Contradiction in RFC 2284

From: "Glen Zorn" <[email-masked]>
Date: Tue, 21 Apr 1998 12:23:10 -0700

RFC 2284 appears to be self contradicting WRT to the contents of the
Type-Data field of the Nak authentication type: section 2.2.1 on page 7 says

   Type

      The Type field is one octet.  This field indicates the Type of
      Request or Response.  Only one Type MUST be specified per EAP
      Request or Response.  Normally, the Type field of the Response
      will be the same as the Type of the Request.  However, there is
      also a Nak Response Type for indicating that a Request type is
      unacceptable to the peer.  When sending a Nak in response to a
                                                    ------------------------
---------------------------
      Request, the peer MAY indicate an alternative desired
      ----------------------------------------------------------------------
----
      authentication Type which it supports.
      ---------------------------------------------------
      An initial specification of
      Types follows in a later section of this document.

   Type-Data

      The Type-Data field varies with the Type of Request and the
      associated Response.

but section 3.3 on page 10 says

    3.3.  Nak

   Description

      The Nak Type is valid only in Response messages.  It is sent in
      reply to a Request where the desired authentication Type is
      unacceptable.   Authentication Types are numbered 4 and above.
      The Response contains the authentication Type desired by the peer.

   Type

      3

   Type-Data

      This field MUST contain a single octet indicating the desired
       ---------------------------------------------------------------------
-------------
      authentication type.
      --------------------------

Which is it, MAY or MUST?