Subject: Fwd: Last Call: 'RADIUS Delegated-IPv6-Prefix Attribute' to Proposed Standard (draft-ietf-radext-delegated-prefix)

From: Bob Hinden <[email-masked]>
Date: Fri, 26 May 2006 11:02:54 -0700

FYI.  Has anyone looked at this?  From the Introduction:

    1.  Introduction

    The Delegated-IPv6-Prefix is a RADIUS attribute [1] that carries an
    IPv6 prefix to be delegated to the user.  For example, the prefix in
    a Delegated-IPv6-Prefix attribute can be delegated to another node
    through DHCP Prefix Delegation [2].

I infer from this that the intent is for a DHCPv6 server to get a  
prefix from an Radius/Diameter authentication check it will later  
delegate to the user.   This seems OK to me, but it would also seem  
to provide for another general way to delegate IPv6 prefixes.  I  
think that the draft needs more explination on it's intended usage.    
Or is this an IPv6 version of something that exists in IPv4?

Comments?

Bob

Begin forwarded message:

> From: "ext The IESG" <[email-masked]>
> Date: May 26, 2006 6:50:41 AM PDT
> To: IETF-Announce <[email-masked]>
> Cc: [email-masked]
> Subject: Last Call: 'RADIUS Delegated-IPv6-Prefix Attribute' to  
> Proposed  Standard (draft-ietf-radext-delegated-prefix)
> Reply-To: [email-masked]
>
> The IESG has received a request from the RADIUS EXTensions WG to  
> consider the
> following document:
>
> - 'RADIUS Delegated-IPv6-Prefix Attribute '
>    <draft-ietf-radext-delegated-prefix-01.txt> as a Proposed Standard
>
> The IESG plans to make a decision in the next few weeks, and solicits
> final comments on this action.  Please send any comments to the
> [email-masked] or [email-masked] mailing lists by 2006-06-09.
>
> The file can be obtained via
> http://www.ietf.org/internet-drafts/draft-ietf-radext-delegated- 
> prefix-01.txt
>
>
> _______________________________________________
> IETF-Announce mailing list
> [email-masked]
> https://www1.ietf.org/mailman/listinfo/ietf-announce

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From: Ralph Droms <[email-masked]>
Date: Fri, 26 May 2006 14:12:14 -0400

Bob - RFC 3633 [2] suggests the use of Framed-IPv6-Prefix option to carry
the customer prefix from the provisioning database through RADIUS to the
DHCPv6 PD delegating router.  That use of Framed-IPv6-Prefix overloads other
uses of the attribute to carry the prefix to be assigned to the link between
the NAS and the CPE.  This new I-D defines a new RADIUS attribute to be used
expressly for a prefix to be delegated to the CPE for use in the network
behind the CPE.

- Ralph

---

From: Bob Hinden <[email-masked]>
Date: Fri, 26 May 2006 11:23:55 -0700

Ralph,

> expressly for a prefix to be delegated to the CPE for use in the  

Thanks for the explanation!  I think it would be good if something  
like the above text was added to the draft.  The current text can be  
interpreted in several ways and seems to allow other usage.  For  
example, the scenario you describe is cited as an example.

Note: I am not against do this at all, I just want the document to be  
clear in it's intended usage.

Thanks,
Bob

---

From: Ralph Droms <[email-masked]>
Date: Fri, 26 May 2006 14:36:13 -0400

Bob - the draft used to contain the following text:

   The Delegated-IPv6-Prefix attribute is related to the Framed-IPv6-
   Prefix attribute [1]; it differs from the Framed-IPv6-Prefix
   attribute in its intended usage.  The prefix in the Delegated-IPv6-
   Prefix attribute is delegated to another entity, while the Framed-
   IPv6-Prefix attribute is under the control of the NAS.  For example,
   the prefix in a Delegated-IPv6-Prefix attribute can be delegated to
   another node through DHCP Prefix Delegation [2], while the prefix in
   a Framed-IPv6-Prefix attribute can be assigned to a link to which the
   NAS is attached, and subsequently advertised through Router
   Advertisement messages [3].

   [1]  Aboba, B., Zorn, G., and D. Mitton, "RADIUS and IPv6", RFC 3162,
        August 2001.

   [2]  Troan, O. and R. Droms, "IPv6 Prefix Options for Dynamic Host
        Configuration Protocol (DHCP) version 6", RFC 3633,
        December 2003.

   [3]  Narten, T., Nordmark, E., and W. Simpson, "Neighbor Discovery
        for IP Version 6 (IPv6)", RFC 2461, December 1998.

But this text extrapolates a bit on the text that actually appears in RFC
3162, and the inclusion of the text here started a discussion about the
intended use of the Framed-IPv6-Prefix.  So, to avoid entanglements with any
revisions to RFC 3162, draft-ietf-radext-delegated-prefix simply remains
silent on the issue.

- Ralph

---

From: Bob Hinden <[email-masked]>
Date: Fri, 26 May 2006 14:15:11 -0700

Ralph,

Thanks, but I think I am now more confused. I draw the opposite  
conclusion if the planned usage is different from what is in  
RFC3162.  How is an implementor supposed to know this if it isn't  
written down?

For now, I suggest treating this issue as an response to the IETF  
last call.

Thanks,
Bob