Re: [v6ops] draft-ietf-6man-grand : saving lookups

Philip Homburg <> Tue, 11 August 2020 08:28 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id 9F2F63A0E71; Tue, 11 Aug 2020 01:28:12 -0700 (PDT)
X-Quarantine-ID: <s1kn_mCLZzjF>
X-Virus-Scanned: amavisd-new at
X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "Cc"
X-Spam-Flag: NO
X-Spam-Score: -1.686
X-Spam-Status: No, score=-1.686 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, KHOP_HELO_FCRDNS=0.212, SPF_HELO_NONE=0.001, SPF_NONE=0.001] autolearn=no autolearn_force=no
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id s1kn_mCLZzjF; Tue, 11 Aug 2020 01:28:11 -0700 (PDT)
Received: from ( [IPv6:2001:888:1044:10:2a0:c9ff:fe9f:17a9]) (using TLSv1.2 with cipher ECDHE-RSA-CHACHA20-POLY1305 (256/256 bits)) (No client certificate requested) by (Postfix) with ESMTPS id B70EE3A0D78; Tue, 11 Aug 2020 01:28:09 -0700 (PDT)
Received: from (localhost [::ffff:]) by with esmtp (TLS version=TLSv1.2 cipher=ECDHE-RSA-CHACHA20-POLY1305) (Smail #157) id m1k5Pdd-0000KfC; Tue, 11 Aug 2020 10:28:05 +0200
Message-Id: <>
Cc: Jen Linkova <>
Cc: 6man <>
From: Philip Homburg <>
References: <> <> <> <> <> <> <> <> <> <>
In-reply-to: Your message of "Sun, 9 Aug 2020 19:28:51 +1000 ." <>
Date: Tue, 11 Aug 2020 10:28:05 +0200
Archived-At: <>
Subject: Re: [v6ops] draft-ietf-6man-grand : saving lookups
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: v6ops discussion list <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Tue, 11 Aug 2020 08:28:13 -0000

In your letter dated Sun, 9 Aug 2020 19:28:51 +1000 you wrote:
>I guess we can add to the very end of the Section 4.1.2 (the new text):
>"A node MAY send unsolicited NAs for its preferred addresses
>periodically to refresh the Neighbor Cache on the first hop routers."
>On the other hand it might pollute the router NC with entries for
>addresses which the node has configured but is not going to use.
>What does the WG think?

A few thoughts:

1) It has to specified how often the host has to refresh entries

2) I think MAY is too weak to rely on. One possibility to deal with 1)
   and 2) is to have an RA option that specifies the interval. Then we
   can make sending the NAs if the option is present a SHOULD or MUST

3) What happens if there are more entries then fit in the router's NC?

4) It has been argued against DHCPv6 IA_NA that hosts may need more 
   addresses than can be handled by the DHCP server. There is an RFC
   that says something to that effect. If so, then we can expect
   more address than can be handled by the router NC as well. I think
   we need to be consistent here. Or is this only for some special 
   networks where host have only few addresses?
   can also expect hoss

5) Hosts have to inform all routers, so this would require hosts to track
   all routers and just a few of them

6) It seems to me that this would something for a new draft