Re: [dhcwg] I-D Action: draft-ietf-dhc-problem-statement-of-mredhcpv6-08.txt

Alan DeKok <> Fri, 19 November 2021 13:52 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id 55F023A0931 for <>; Fri, 19 Nov 2021 05:52:53 -0800 (PST)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -1.899
X-Spam-Status: No, score=-1.899 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id CQ1N4mVGq9n6 for <>; Fri, 19 Nov 2021 05:52:49 -0800 (PST)
Received: from ( []) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by (Postfix) with ESMTPS id F28A03A0926 for <>; Fri, 19 Nov 2021 05:52:48 -0800 (PST)
Received: from [] ( []) by (Postfix) with ESMTPSA id D3AF1232 for <>; Fri, 19 Nov 2021 13:52:45 +0000 (UTC)
Authentication-Results: NetworkRADIUS; dmarc=none (p=none dis=none)
From: Alan DeKok <>
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
Mime-Version: 1.0 (Mac OS X Mail 13.4 \(3608.\))
Date: Fri, 19 Nov 2021 08:52:44 -0500
References: <>
In-Reply-To: <>
Message-Id: <>
X-Mailer: Apple Mail (2.3608.
Archived-At: <>
Subject: Re: [dhcwg] I-D Action: draft-ietf-dhc-problem-statement-of-mredhcpv6-08.txt
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Dynamic Host Configuration <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Fri, 19 Nov 2021 13:52:53 -0000

  I have some minor feedback.

  The link to the "ISC kea hook developers guide" is to a page which says "access denied".  Perhaps this link is better:

  Section 1 says in part:

   Some people would suggest that administrators modify the open-source
   DHCPv6 server to solve their problems.  However, it takes
   considerable time to understand the code of an open-source DHCPv6
   server, not to mention the time-consuming task of debugging errors,

  This comment isn't true of all Open Source DHCP servers.  Some can be extended only via source code changes.  Others such as FreeRADIUS support a policy language.  The policy language permits basic if / then / else functions, and option creation, validation, modification, and deletion.

  Similar text to this is in Section 3.2 and in Section 5.2.  It should clarify that there are many ways of writing policies for DHCP servers, not all of which require source code changes.

  Section 4.2.2 has good discussion of options.  But it stops at a problem statement, without addressing implementations (as is done in the other sections).  For example, Kea supports custom options:

  FreeRADIUS has similar support.  The benefit of this approach is that the software can be updated to support new options via a configuration file.  And it does not require any source code changes. 

  This practice means that a particular release of a DHCP server implementation can have a lifetime much longer than would otherwise be possible.

  Alan DeKok.