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[address-policy-wg] WG: Question regarding RIPE-738 IPv6-Policy

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Kurt Kayser

2020-07-23 16:40:38 CET

Dear RIPE members and community,

We have come across a question of correct interpretation for "utilization" wthin´the current "IPv6 Address Allocation and Assignment Policy" RIPE-738 document:

5.2.2. Applied HD-Ratio

The HD-Ratio value of 0.94 is adopted as indicating an acceptable address utilisation for justifying the allocation of additional address space.

Appendix A provides a table showing the number of assignments that are necessary to achieve an acceptable utilisation value for a given address block size.

[...]
10. Appendix A: HD-Ratio

The utilisation threshold T, expressed as a number of individual /56 prefixes to be allocated from IPv6 prefix P, can be calculated as:

T = 2((56-P)*HD)

Thus, the utilisation threshold for an LIR requesting subsequent allocation of IPv6 address block is specified as a function of the prefix size and target HD ratio.

This utilisation refers to the use of /56s as an efficiency measurement unit, and does not refer to the utilisation of addresses within those End Sites.

It is an address allocation utilisation ratio and not an address assignment utilisation ratio.

[...]

The two underlined sentences seem to contradict each other.
For a correct interpretation and calculation of the HD-Ratio/Utilization-Threshold (T) for IPv6-subsequent block eligibility, what is now correct "allocation" or "assignment" ?

In the LIR-Portal there is an %-indication for "my own resources" which soley refers to assignments within a specific block. Allocations seem not to be considered.

What is the correct way to calculcate the utilization?

Best regards,
on behalf
Kurt Kayser
_______________________
Kurt Kayser Konsultation
im Auftrag des Referates SK 4 - Konzeption/ Local Internet Registry
Bundesanstalt für den Digitalfunk der Behörden und Organisationen mit Sicherheitsaufgaben (BDBOS)
Telefon: +49 (0) 1575-2634020
E-Mail: Kurt.Kayser _at_ bmi.bund _dot_ deKurt.Kayser _at_ bmi.bund _dot_ de>
Internet: www.bdbos.bund.de

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Gert Doering

2020-07-23 16:53:12 CET

Hi Kurt,

On Thu, Jul 23, 2020 at 02:40:38PM +0000, Kurt.Kayser _at_ bmi.bund _dot_ de wrote:
> What is the correct way to calculcate the utilization?

Count /56s assigned.  /48s count as 256x /56.  Look up /56 count in the
HD ratio table.

The confusing sentence is supposed to convey "we care about efficiency
of usage inside the 'allocation' arena", so "/56 or /48 inside the /32
or larger".  We do not care about efficiency in the "assigned chunk",
so in the /56 we do not care if 1 address was used or 100.

(Which is different from IPv4, so it ended up in this - very old - text)

Less confusing now?  Or did I make it worse?

Gert Doering
        -- NetMaster
-- 
have you enabled IPv6 on something today...?

SpaceNet AG                      Vorstand: Sebastian v. Bomhard, Michael Emmer
Joseph-Dollinger-Bogen 14        Aufsichtsratsvors.: A. Grundner-Culemann
D-80807 Muenchen                 HRB: 136055 (AG Muenchen)
Tel: +49 (0)89/32356-444         USt-IdNr.: DE813185279
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Kurt Kayser

2020-07-24 10:37:31 CET

Hello Gert,

thanks for clarification. The main sentence that confused me was this in Appendix A:
" It is an address allocation utilisation ratio and not an address assignment utilisation ratio."

What you now explain still defines a classical "assignment utilization rate" with a limted look up to a /56 granularity.
I assume the misinterpretation is the second part which does not require "full subnets", hence again the term "allocation".

So there are 3 parts to correctly calculate HD-ratios:
1. IP-Allocation from RIR to LIRs
2. Assignments for true use from LIR to endsites/users/devices - to be counted as /56 or /48 units (as shown as "used" in the LIR portal)
3. All networks below /56 that are assigned are not to be evaluated deeper about efficient usage.

Correct?

Best regards
On behalf
Kurt Kayser
_______________________
Kurt Kayser Konsultation
im Auftrag des Referates SK 4 - Konzeption/ Local Internet Registry
Bundesanstalt für den Digitalfunk der Behörden und Organisationen mit Sicherheitsaufgaben (BDBOS)
Telefon: +49 (0) 1575-2634020
E-Mail: Kurt.Kayser _at_ bmi.bund _dot_ de
Internet: www.bdbos.bund.de

-----Ursprüngliche Nachricht-----
Von: Gert Doering <gert _at_ space _dot_ net> 
Gesendet: Donnerstag, 23. Juli 2020 16:53
An: Kayser (Extern), Kurt <Kurt.Kayser _at_ bmi.bund _dot_ de>
Cc: address-policy-wg _at_ ripe _dot_ net
Betreff: Re: [address-policy-wg] WG: Question regarding RIPE-738 IPv6-Policy

Hi Kurt,

On Thu, Jul 23, 2020 at 02:40:38PM +0000, Kurt.Kayser _at_ bmi.bund _dot_ de wrote:
> What is the correct way to calculcate the utilization?

Count /56s assigned.  /48s count as 256x /56.  Look up /56 count in the
HD ratio table.

The confusing sentence is supposed to convey "we care about efficiency
of usage inside the 'allocation' arena", so "/56 or /48 inside the /32
or larger".  We do not care about efficiency in the "assigned chunk",
so in the /56 we do not care if 1 address was used or 100.

(Which is different from IPv4, so it ended up in this - very old - text)

Less confusing now?  Or did I make it worse?

Gert Doering
        -- NetMaster
-- 
have you enabled IPv6 on something today...?

SpaceNet AG                      Vorstand: Sebastian v. Bomhard, Michael Emmer
Joseph-Dollinger-Bogen 14        Aufsichtsratsvors.: A. Grundner-Culemann
D-80807 Muenchen                 HRB: 136055 (AG Muenchen)
Tel: +49 (0)89/32356-444         USt-IdNr.: DE813185279