Re: [v6ops] draft-ietf-v6ops-host-addr-availability discussion

David Farmer <> Tue, 03 November 2015 07:40 UTC

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To: Lorenzo Colitti <>
From: David Farmer <>
Organization: University of Minnesota
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Date: Tue, 3 Nov 2015 01:40:13 -0600
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Subject: Re: [v6ops] draft-ietf-v6ops-host-addr-availability discussion
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On 11/2/15 22:38 , Lorenzo Colitti wrote:
> David,
> that statement makes sense, but I'm worried about scope creep. The
> document is focused on recommendations to network operators; if we start
> adding recommendations to hosts as well, that might well change the
> scope of the draft substantially, and might be the start of a process
> that results in a large amount of text being added and takes substantial
> time to complete.

I'm sensitive to the scope creep issue.  However, you are asking network 
operators to take all the risk and to change they way they do things. 
Yes, it's old IPv4 thinking and we have to find the new normal for IPv6. 
  But, a little balance asking hosts and applications to not break the 
networks if the network operates open things up would be some 

I'm asking for a little bit of a social contract here, basically the 
deal is I won't nail down all the 2x4s if you promise not to pick them 
up and beat me over the head with them.  But, if your not even willing 
to tell me you won't beat me over the head with the 2x4s, why would I 
ever not nail them all down.

> Example: adding that recommendation to the recommendations section might
> result in criticism that that recommendation is not adequately
> justified/motivated by the rest of the draft's text. The response to
> that criticism might be to add text to the draft to motivate it, but
> that text would obviously need to go through the WG, we'd have to gain
> consensus on it, etc.
> Also, on the text itself: if a host is given an IPv6 prefix via DHCPv6
> PD, I don't know if it's "excessive and unjustified" for it to decide,
> for example, to use a different IPv6 address for each server it talks
> to. The extra load on the network might well be nil.

I'm not stuck on those words, I'm just looking for something that 
acknowledges if networks impose no hard limit on the number of IPv6 
addresses, that is not a excuse for hosts and applications to go crazy.

Furthermore, I'm a little worried if I set a threshold of lets say 1000 
IPv6 addresses and then quarantine a host as a network abuser, am I 
violating the spirit of this draft? Is 500 too low? 250?

Maybe you can think of a different way to cover this.


> Cheers,
> Lorenzo
> On Tue, Nov 3, 2015 at 11:11 AM, David Farmer <
> <>> wrote:
>     I thought I brought up this issue previously, but I'd like to see
>     something addressing excessive use of addresses, maybe adding this
>     as an additional paragraph in section 8, recommendations.
>         Conversely, it is RECOMMENDED that hosts and applications not
>         excessively consume IPv6 addresses, such as generating a new address
>         for every connection or with excessive frequency, for instance every
>         few minutes or seconds.  A general-purpose host utilizing several
>         hundreds or thousands of IPv6 addresses seems excessive and
>         unjustified in most situations. This could evoke network operators
>         to deploy DHCPv6 simply to apply sanity limits on the number of
>         IPv6 addresses available per host.
>     On 11/1/15 23:15 , Fred Baker (fred) wrote:
>         In the discussion this morning, we wound up in a position that I
>         could not call "consensus", even "rough consensus", but per a
>         hum of those in the room, within shouting distance of achieving
>         that. Several people spoke at the mike asking for a sentence or
>         brief discussion to be added, or a section clarified.
>         In the interest of expediency, let me ask those who spoke (and
>         anyone else that has an issue) to respond to this note (copying
>         the list) with suggested text. It might be best if this is stated as
>         OLD TEXT
>         the text that should be replaced goes here
>         NEW TEXT
>         the text that should replace it goes here
>         or
>         LOCATION
>         identify the section the text should go into
>         the text that should be added goes here
>         I'll permit the authors to declare suggested text out of scope;
>         some of the discussion this morning left them commenting on
>         scope and scope creep. However, I do ask them to justify the
>         exclusion to the list, rather than just ignore the email.
>         This comment period ends 15 November.
>         _______________________________________________
>         v6ops mailing list
> <>
>     --
>     ================================================
>     David Farmer               Email: <>
>     Office of Information Technology
>     University of Minnesota
>     2218 University Ave SE     Phone: 1-612-626-0815
>     Minneapolis, MN 55414-3029  Cell: 1-612-812-9952
>     ================================================
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David Farmer               Email:
Office of Information Technology
University of Minnesota
2218 University Ave SE     Phone: 1-612-626-0815
Minneapolis, MN 55414-3029  Cell: 1-612-812-9952