Re: [dhcwg] Last Call: <draft-ietf-dhc-option-guidelines-14.txt> (Guidelines for Creating New DHCPv6 Options) to Best Current Practice

"Bernie Volz (volz)" <> Sat, 12 October 2013 14:26 UTC

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From: "Bernie Volz (volz)" <>
To: Ted Lemon <>, Sten Carlsen <>
Thread-Topic: [dhcwg] Last Call: <draft-ietf-dhc-option-guidelines-14.txt> (Guidelines for Creating New DHCPv6 Options) to Best Current Practice
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Date: Sat, 12 Oct 2013 14:26:12 +0000
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Subject: Re: [dhcwg] Last Call: <draft-ietf-dhc-option-guidelines-14.txt> (Guidelines for Creating New DHCPv6 Options) to Best Current Practice
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Two points:

1. A server should NOT be required to do a "fresh" lookup if the TTL for the DNS information has not expired [or it not close to expiring].

2. This doesn't solve all of the issues since the DNS TTL, as Ted has pointed out in some discussions, is not generally related to the lease (or renewal) time. Thus, it really depends on when the client is expected to use this information which could be long after the TTL for the original DNS query has expired.

Hence, depending on when a client is expected to use this information should greatly influence the decision as to whether to define an option as an FQDN or address(es). For example, for a next step bootstrap loader (or configuration file such as for DOCSIS), an address is fine as this is expected to be used by the client almost immediately. Something that may be used hours or days later when a user requests a particular application really SHOULD use an FQDN.

- Bernie

-----Original Message-----
From: [] On Behalf Of Ted Lemon
Sent: Thursday, October 10, 2013 10:46 AM
To: Sten Carlsen
Cc: WG
Subject: Re: [dhcwg] Last Call: <draft-ietf-dhc-option-guidelines-14.txt> (Guidelines for Creating New DHCPv6 Options) to Best Current Practice

On Oct 10, 2013, at 10:45 AM, Sten Carlsen <> wrote:
> What about requiring that it does a fresh lookup, IF it has the server specified as an FQDN? If it is only specified as an IP, obviously there is no option for lookup.

I think you just answered your own question. :)

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