Re: [dhcwg] I-D Action: draft-ietf-dhc-dhcpv6-client-link-layer-addr-opt-02.txt

"Bernie Volz (volz)" <> Fri, 21 September 2012 14:46 UTC

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From: "Bernie Volz (volz)" <>
To: Bud Millwood <>, "" <>
Thread-Topic: [dhcwg] I-D Action: draft-ietf-dhc-dhcpv6-client-link-layer-addr-opt-02.txt
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Subject: Re: [dhcwg] I-D Action: draft-ietf-dhc-dhcpv6-client-link-layer-addr-opt-02.txt
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I do like "inner-most Relay-Forw" (i.e. the relay that received the client's packet [msg-type != Relay-Forw]).

While in theory a MUST is probably correct, there might be cases where that doesn't work? So, I would lean towards SHOULD to potentially support cases where there might be a second (the next) relay that has this information [and the first does not]? Certainly the MUST is correct for traditional applications (i.e. corporate Ethernet based networks or CableLabs DOCSIS).

I can't give you a specific example, but perhaps there are some from networks that don't support multicast or where a relay proxy is needed on the device itself (as then you'd have the client providing this information)?

- Bernie

-----Original Message-----
From: [] On Behalf Of Bud Millwood
Sent: Friday, September 21, 2012 9:55 AM
Subject: Re: [dhcwg] I-D Action: draft-ietf-dhc-dhcpv6-client-link-layer-addr-opt-02.txt

5.  DHCPv6 Server Behavior

> If DHCPv6 Server is configured to store or use client link-layer address, it SHOULD look for the client link-layer address option in the RELAY-FORW DHCP message of the DHCPv6 Relay agent closest to the client.

Although I understand what "closest to the client" means (I use that term myself), is that the correct terminology? It could also be referred to as the inner-most RELAY-FORW message, or the first RELAY-FORW message. Is there even a standard terminology for this? I just glanced through 3315 and don't see anything.

Also, the server "SHOULD" look for the link-layer address in the closest RELAY-FORW message. What are the ramifications of changing this to MUST? Is there any scenario where a second-hop relay would know the link-layer address, but the first hop wouldn't know it or support this RFC? Do we gain anything by enforcing that a conveyed link-layer address is only valid or to be trusted if it's from the first-hop relay?

- Bud

On Fri, Sep 21, 2012 at 12:34 PM,  <> wrote:
> A New Internet-Draft is available from the on-line Internet-Drafts directories.
>  This draft is a work item of the Dynamic Host Configuration Working Group of the IETF.
>         Title           : Client Link-layer Address Option in DHCPv6
>         Author(s)       : Gaurav Halwasia
>                           Shwetha Bhandari
>                           Wojciech Dec
>         Filename        : draft-ietf-dhc-dhcpv6-client-link-layer-addr-opt-02.txt
>         Pages           : 6
>         Date            : 2012-09-21
> Abstract:
>    This document specifies the format and mechanism that is to be used
>    for encoding client link-layer address in DHCPv6 relay forward
>    messages by defining a new DHCPv6 Client Link-layer Address option.
> The IETF datatracker status page for this draft is:
> er-addr-opt
> There's also a htmlized version available at:
> r-opt-02
> A diff from the previous version is available at:
> er-addr-opt-02
> Internet-Drafts are also available by anonymous FTP at:
> _______________________________________________
> dhcwg mailing list
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