Subject: [dhcwg] New draft on DHCPv6 Relay Information Option and RADIUS Attributes sub-option

From: Wing Cheong Lau <[email-masked]>
Date: Fri, 22 Oct 2004 09:44:30 -0700

Dear all,

We have submitted a new draft on DHCPv6 Relay Information Option and RADIUS 
Attributes sub-option last week. It's already available from the ietf site

http://www.ietf.org/internet-drafts/draft-droms-dhc-v6-relayopt-00.txt

but I have not seen the official announcement so far.

The draft basically carries over similar capabilities, namely,
RFC 3046 and draft-ietf-dhc-agentopt-radius-08.txt
from DHCPv4 to DHCPv6,  with initial use cases targetting for
the 3GPP2 environment.

Comments are welcome.

Regards,

Wing

Abstract

    This document introduces the capabilities of the DHCPv4 Relay Agent
    Information Option in RFC 3046 and the corresponding RADIUS-
    Attributes Sub-option to DHCPv6. In particular, the document
    describes a new DHCPv6 option called the Relay Agent Information
    option which extends the set of DHCPv6 options as defined in RFC 3315
    and 3376. Following its DHCPv4 counterpart as defined in RFC 3046,
    the new option is inserted by the DHCPv6 relay agent when forwarding
    client-originated DHCPv6 packets to a DHCPv6 server. Servers
    recognizing the Relay Agent Information option may use the
    information to implement IP address or other parameter assignment
    policies.  The DHCP Server echoes the option back verbatim to the
    relay agent in server-to-client replies, and the relay agent strips
    the option before forwarding the reply to the client. The Relay Agent
    Information option is organized as a single DHCPv6 option that
    contains one or more "sub-options" that convey information known by
    the relay agent.  A RADIUS Attributes Sub-option, following its
    DHCPv4 counterpart, is also defined.   

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

---

From: "Bernie Volz" <[email-masked]>
Date: Fri, 22 Oct 2004 17:41:17 -0400

A very basic question ... why have a Relay Agent Information option and have
sub-options inside this? And, especially 8-bit suboptions.
 
It seems to me that with the larger 16-bit DHCPv6 option space, we'd just
define an option to carry the "Radius Attributes" instead of placing this
under a general "Relay Agent" option. The context of the message is pretty
clear -- if it is from the relay, it can only be in a Relay-Forw (and
Relay-Reply) message option area.
 
There's also another advantage to this. Take the DHCPv4 subnet-selection
option - there are two forms of this, one in for the relay agent and another
for the client. This won't be necessary in DHCPv6 as the LOCATION of the
message (either in the Client's Solicit, Request, ... or in a
Relay-Forw/Relay-Reply) tells us who added it and which we'd prefer to use.
This means only ONE option number is needed.
 
So, I'd much rather see this specify a base option,
OPTION-RADIUS-ATTRIBUTES, and have this contain the Radius attributes in the
standard Radius encoding. So, it is just 16-bit option code, 16-bit length,
followed by the radius encoding (as 8-bit suboptions).
 
You can then specify that OPTION-RADIUS-ATTRIBUTES can only appear in the
Relay-Forw (and Relay-Reply) message and MUST NOT appear in client messages
themselves.
 
- Bernie

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf Of
Wing Cheong Lau
Sent: Friday, October 22, 2004 12:45 PM
To: [email-masked]
Subject: [dhcwg] New draft on DHCPv6 Relay Information Option and RADIUS
Attributes sub-option

Dear all,

Comments are welcome.

Regards,

Wing

Abstract

---

From: Ted Lemon <[email-masked]>
Date: Fri, 22 Oct 2004 17:17:48 -0700

Er, furthermore there's already a relay encapsulation method defined in 
the base DHCPv6 specification.

---

From: "Bernie Volz" <[email-masked]>
Date: Fri, 22 Oct 2004 23:05:07 -0400

Ted:

Not sure what you're referring to.

A relay would normally take a client message and place it into a Relay-Forw
with a Relay Message option containing the client's message. It can also add
any other options that it wants (and are allowed). In the base spec, this
might include an Interface-ID option, for example. And, why I suggested was
that this new I-D just define a "Radius Attribute" option which the Relay
Agent would add into the Relay-Forw message.

- Bernie

> From: Ted Lemon [mailto:[email-masked]] 
> Sent: Friday, October 22, 2004 8:18 PM
> To: Bernie Volz
> Cc: [email-masked]; 'Ralph Droms'; 'Wing Cheong Lau'
> Subject: Re: [dhcwg] New draft on DHCPv6 Relay Information 
> Option and RADIUS Attributes sub-option
> 
>

---

From: Ted Lemon <[email-masked]>
Date: Fri, 22 Oct 2004 22:02:20 -0700

> Agent would add into the Relay-Forw message.

Right, that's what I was referring to.   :')