RE: [address-policy-wg] last Call: Policy proposal #beta HD rati o policy proposal
From my point of view, I would like to see the current policy remain in place, because with IPv4 we much more have a conservation
Hello Hans Petter and al, I am AGAINST the proposal. I would like Alain to better explain his need for better IP address management. He is the only voice I have seen *for* the proposal. Nobody is supporting Alain, instead Iljitsch has brought profound comments *against*, and there were some cynic comments - also *against*. than an aggregation goal (or an internal aggregation need) Large LIRs already receive /10s and I cannot see the proposal will have "some limited impact" on address consumption. If giant LIRs will only be mandated to occupy 52% instead of 80% of their v4-IPs (I have done this calculation for DTAG and FT), this is in my view going to cut our resources significantly. So, does the new PDP request a counter proposal to maintain current policy, I guess no, just enough people have to say no. Also, people in support of the proposal please raise your hands. regards Karsten eu.lambdanet
-----Original Message----- From: Hans Petter Holen [mailto:hpholen@tiscali.no] Sent: Friday, July 01, 2005 12:37 AM Cc: address-policy-wg@ripe.net Subject: [address-policy-wg] last Call: Policy proposal #beta HD ratio policy proposal
Hans Petter Holen wrote: Following the discussion on the mailinglist prior to and after posting the formal proposal I have seen no proposals to modify the proposal and would like to move the proposal into the conclustion phase in the policy development process http://www.ripe.net/ripe/draft-documents/pdp.html
Last cal will end at July 15th.
Best Regards
Hans Petter Holen WG Chair
Thanks Alain, I'll as the new PDP is not in operation yet, I'll add this to my list as #beta v1
I propose that we enter into the Discussion phase for 4 weeks from date until April 4.
-hph
BIDRON Alain ROSI/DAS wrote:
Dear Colleagues Referring to the minutes of the last RIPE Policy Working Group meeting and to the action list as updated during that meeting, I have to make a formal proposal on use of HD ratio for IPV4. Here is this policy proposal. In order to be consistent with the PDP Draft proposal coming from Rob Blokzijl I have used the template provided in the new PDP proposal. Best regards. Alain
_________________________________________________________ 1. Policy Proposal Name: IPv4-HD-Ratio 2. Author a. name: Alain Bidron b. e-mail: alain.bidron@francetelecom.com c. telephone: +33 1 44 44 27 75 d. organisation: France Telecom 3. Proposal Version: V0 4. Submission Date: 02/02/2005 5. Suggested WG for discussion and publication: Address Policy WG 6. Proposal type: modify 7. Policy term: permanent 8. Summary of proposal: Internet address space is managed hierarchically: - IANA allocates space to Regional Internet Registries (RIRs). - RIRs allocate space to Local Internet Registries (LIRs). - LIRs assign space to End Users.
At each level, some address space may be reserved for future expansion and/or efficient aggregation. As more hierarchical levels are introduced, the overall efficiency of the address space usage decreases.
The HD ratio (Host-Density ratio) is a way to measure address space usage [RFC 3194]. The HD ratio value can relate to a percentage of usage, which decreases as the amount of address space grows. This allows for the decreasing efficiency that occurs with more hierarchical levels.
The HD ratio is currently used to measure IPv6 address space usage [ipv6-address-policy]. The IPv6 Address Allocation and Assignment Policy considers a block of IPv6 address space to be used when its HD ratio reaches 0.80. This is a manageable figure ("values of 80% or less correspond to comfortable trade-offs between pain and efficiency" [RFC 3194]).
This document proposes using the HD ratio to measure IPv4 usage. The proposed value of the HD ratio for IPv4 is 0.96.
9. Policy text: a. Current: "An LIR may receive an additional allocation when about eighty percent (80%) of all the address space currently allocated to it is used in valid assignments or sub-allocations." b. New: "An LIR may receive an additional allocation when its total allocated address space usage meets the HD-Ratio value of 0.96."
10. Rationale:
a. Background The current document, IPv4 Address Allocation and Assignment Policies for the RIPE NCC Service Region [ipv4-address-policy], considers a block of IPv4 addresses to be used when 80% of the addresses within the block have been sub-allocated or assigned. This is applied to all address blocks, regardless of size. Current policies assume a hierarchical system of address space delegation. However, they do not make any allowance for hierarchical management within allocated address space. For LIRs in particular, a hierarchical approach is often required for assignment of address space to service elements such as customer networks, individual Points of Presence (PoPs), regionalised topologies, and even distinct ISP products. Small network infrastructures may require simple hierarchies, but large infrastructures can require several levels of address space subdivision. These levels of hierarchy are not recognised by the current policy framework and are highly restricted by the "80% rule". As a result, managing large blocks is often difficult, requiring large internal routing tables and/or frequent renumbering of internal address blocks.
One of the goals of the RIR system is to avoid unnecessary depletion of IPv4 address space. However, address management policies must also be practical in terms of how much management overhead they cause. When large amounts of address space are involved, the "80% rule" can result in more work for an LIR.
Basing usage on the HD ratio should lead to equal levels of management overhead across the board, rather than penalising the holders of large address blocks.
b.Impact To see a rough estimation of the immediate impact of this proposal, an HD Ratio value of 0.96 was applied to the average amount of address space held by an LIR in the RIPE NCC Service Region. This showed that on average, LIRs would qualify for an additional allocation block when they have assigned or sub-allocated about 59% of their allocated address space.
c.Arguments supporting the proposal. This proposal fairly takes into account addressing hierarchies used in large and extra-large registries and introduces a useful level of flexibility for those registries The local Internet registries using the 80% criteria may continue to do so and will not be impacted by the new policy. The RIPE NCC will provide support to minimise complicated calculations or administrative burden to LIRs.
d. Arguments opposing the proposal. This proposal will have some limited impact on IPV4 address consumption.
Appendix A. The HD ratio
The HD ratio is calculated as follows [RFC 3194]:
HD = log(U)/log(S)
Where:
S is the size of the address block concerned, and U is the number of addresses used.
Note: The current IPv4 policy considers addresses to be used once they are assigned or sub-allocated by the LIR. Appendix B. Selection of HD ratio value
We should decide an appropriate HD ratio value on a rational basis. To do this, we make certain assumptions about the number of "hidden" hierarchical levels involved in managing address blocks of various sizes. If we assume there is 80% usage at each level, we can easily calculate the overall usage.
The following table proposes a set of hierarchical levels which we can reasonably expect within different amounts of address space. If a usage of 80% is achieved at each hierarchical level, then the overall usage will be (0.80 to the power of "n"). It is then possible to calculate HD ratio values from this value.
Size range Level Utilisation HD ratio (prefix) (n) (0.80**n) (calculated) /24 to /20 1 80% .960 to .973 /20 to /16 1.5 72% .961 to .970 /16 to /12 2 64% .960 to .968 /12 to /8 2.5 57.2% .960 to .966 /8 to /4 3 51.20% .960 to .966 The levels of hierarchy listed above are based on assumptions about the likely size and structure of LIRs holding address blocks of these sizes. A reasonable HD ratio value may be 0.96 (a round figure which occurs within most of these ranges) from the table above. The following table gives the usage requirements for IPv4 address blocks from /24 to /8 for this value.
IPv4 Addresses Addresses Util% prefix total used 24 256 205 80.11% 23 512 399 77.92% 22 1024 776 75.79% 21 2048 1510 73.71% 20 4096 2937 71.70% 19 8192 5713 69.74% 18 16384 11113 67.83% 17 32768 21619 65.98% 16 65536 42055 64.17% 15 131072 81811 62.42% 14 262144 159147 60.71% 13 524288 309590 59.05% 12 1048576 602249 57.43% 11 2097152 1171560 55.86% 10 4194304 2279048 54.34% 9 8388608 4433455 52.85% 8 16777216 8624444 51.41%
Note: This table provides values for CIDR blocks, but the same calculations can be made for non-CIDR blocks.
As an example, an LIR holding a total amount of address space equal to a /16 would be able to receive more address space when they had sub-allocated or assigned 64.17% of that space; while an LIR holding a /9 would be able to receive more space when they had sub-allocated or assigned 52.85% of their address space.
Appendix C. References [RFC 3194] "The Host-Density ratio for address assignment efficiency: An update on the H ratio", A. Durand, C.Huitema, November 2001. [ipv6-address-policy] RIPE NCC document: "IPv6 Address Allocation and Assignment Policy" http://www.ripe.net/ripe/docs/ipv6policy.html [ipv4-address-policy] RIPE NCC document: "IPv4 Address Allocation and Assignment Policies for the RIPE NCC Service Region" http://www.ripe.net/ripe/docs/ipv4-policies.html
Hi Karsten, The responses I have seen to the list in favour of the HD ratio to the address-policy mailinglist arefrom * alain.bidron@francetelecom.com * kelaidi@ote.gr * EricS@t-com.net * groeskens@bluewin.ch * debecker@etno.be (on behalf or ETNO in September 2004) From re-reading the entire discussion I see that there has been some discussion on elements that could be interpreted as beeing oppsoed to the proposal as you state - could I ask for clearification from all involved during last call on this so I do not have to interpret language amd make wrong judgement of statements to the list ? As to the procedural point you are quite right that in order to stop this proposal - you need to state - as you did - that you do not support this policy an preferably why. Best Regards, Hans Petter Holen Address Policy WG Chair
Hello Hans Petter and al,
I am AGAINST the proposal.
I would like Alain to better explain his need for better IP address management. He is the only voice I have seen *for* the proposal. Nobody is supporting Alain, instead Iljitsch has brought profound comments *against*, and there were some cynic comments - also *against*.
From my point of view, I would like to see the current policy remain in place, because with IPv4 we much more have a conservation than an aggregation goal (or an internal aggregation need) Large LIRs already receive /10s and I cannot see the proposal will have "some limited impact" on address consumption. If giant LIRs will only be mandated to occupy 52% instead of 80% of their v4-IPs (I have done this calculation for DTAG and FT), this is in my view going to cut our resources significantly.
So, does the new PDP request a counter proposal to maintain current policy, I guess no, just enough people have to say no. Also, people in support of the proposal please raise your hands.
regards Karsten eu.lambdanet
-----Original Message----- From: Hans Petter Holen [mailto:hpholen@tiscali.no] Sent: Friday, July 01, 2005 12:37 AM Cc: address-policy-wg@ripe.net Subject: [address-policy-wg] last Call: Policy proposal #beta HD ratio policy proposal
Hans Petter Holen wrote: Following the discussion on the mailinglist prior to and after posting the formal proposal I have seen no proposals to modify the proposal and would like to move the proposal into the conclustion phase in the policy development process http://www.ripe.net/ripe/draft-documents/pdp.html
Last cal will end at July 15th.
Best Regards
Hans Petter Holen WG Chair
Thanks Alain, I'll as the new PDP is not in operation yet, I'll add this
to my list
as #beta v1
I propose that we enter into the Discussion phase for 4 weeks from date until April 4.
-hph
BIDRON Alain ROSI/DAS wrote:
Dear Colleagues Referring to the minutes of the last RIPE Policy Working Group meeting and to the action list as updated during that
meeting, I have
to make a formal proposal on use of HD ratio for IPV4. Here is this policy proposal. In order to be consistent with the PDP Draft proposal
coming from Rob
Blokzijl I have used the template provided in the new PDP proposal. Best regards. Alain
_________________________________________________________ 1. Policy Proposal Name: IPv4-HD-Ratio 2. Author a. name: Alain Bidron b. e-mail: alain.bidron@francetelecom.com c. telephone: +33 1 44 44 27 75 d. organisation: France Telecom 3. Proposal Version: V0 4. Submission Date: 02/02/2005 5. Suggested WG for discussion and publication: Address Policy WG 6. Proposal type: modify 7. Policy term: permanent 8. Summary of proposal: Internet address space is managed hierarchically: - IANA allocates space to Regional Internet Registries (RIRs). - RIRs allocate space to Local Internet Registries (LIRs). - LIRs assign space to End Users.
At each level, some address space may be reserved for future expansion and/or efficient aggregation. As more
hierarchical levels
are introduced, the overall efficiency of the address space usage decreases.
The HD ratio (Host-Density ratio) is a way to measure
address space
usage [RFC 3194]. The HD ratio value can relate to a percentage of usage, which decreases as the amount of address space grows. This allows for the decreasing efficiency that occurs with more hierarchical levels.
The HD ratio is currently used to measure IPv6 address space usage [ipv6-address-policy]. The IPv6 Address Allocation and Assignment Policy considers a block of IPv6 address space to be
‘used’ when its
HD ratio reaches 0.80. This is a manageable figure
("values of 80% or
less correspond to comfortable trade-offs between pain and efficiency" [RFC 3194]).
This document proposes using the HD ratio to measure IPv4
usage. The
proposed value of the HD ratio for IPv4 is 0.96.
9. Policy text: a. Current: "An LIR may receive an additional allocation
when about
eighty percent (80%) of all the address space currently
allocated to
it is used in valid assignments or sub-allocations." b. New: "An LIR may receive an additional allocation when
its total
allocated address space usage meets the HD-Ratio value of 0.96."
10. Rationale:
a. Background The current document, “IPv4 Address Allocation and Assignment Policies for the RIPE NCC Service Region” [ipv4-address-policy], considers a block of IPv4 addresses to be ‘used’ when 80% of the addresses within the block have been sub-allocated or
assigned. This
is applied to all address blocks, regardless of size. Current policies assume a hierarchical system of address space delegation. However, they do not make any allowance for
hierarchical
management within allocated address space. For LIRs in
particular, a
hierarchical approach is often required for assignment of address space to service elements such as customer networks, individual Points of Presence (PoPs), regionalised topologies, and
even distinct
ISP products. Small network infrastructures may require simple hierarchies, but large infrastructures can require several
levels of
address space subdivision. These levels of hierarchy are not recognised by the current policy framework and are highly
restricted
by the "80% rule". As a result, managing large blocks is often difficult, requiring large internal routing tables and/or frequent renumbering of internal address blocks.
One of the goals of the RIR system is to avoid unnecessary
depletion
of IPv4 address space. However, address management
policies must also
be practical in terms of how much management overhead they cause. When large amounts of address space are involved, the "80%
rule" can
result in more work for an LIR.
Basing usage on the HD ratio should lead to equal levels of management overhead across the board, rather than penalising the holders of large address blocks.
b.Impact To see a rough estimation of the immediate impact of this
proposal,
an HD Ratio value of 0.96 was applied to the average amount of address space held by an LIR in the RIPE NCC Service Region. This showed that on average, LIRs would qualify for an additional allocation block when they have assigned or sub-allocated
about 59%
of their allocated address space.
c.Arguments supporting the proposal. This proposal fairly takes into account addressing
hierarchies used
in large and extra-large registries and introduces a
useful level of
flexibility for those registries The local Internet registries using the 80% criteria may
continue to
do so and will not be impacted by the new policy. The RIPE NCC will provide support to minimise complicated calculations or administrative burden to LIRs.
d. Arguments opposing the proposal. This proposal will have some limited impact on IPV4
address consumption.
Appendix A. The HD ratio
The HD ratio is calculated as follows [RFC 3194]:
HD = log(U)/log(S)
Where:
S is the size of the address block concerned, and
U is
the number of addresses used.
Note: The current IPv4 policy considers addresses to be
‘used’ once
they are assigned or sub-allocated by the LIR. Appendix B. Selection of HD ratio value
We should decide an appropriate HD ratio value on a
rational basis.
To do this, we make certain assumptions about the number
of "hidden"
hierarchical levels involved in managing address blocks of various sizes. If we assume there is 80% usage at each level, we
can easily
calculate the overall usage.
The following table proposes a set of hierarchical levels which we can reasonably expect within different amounts of address
space. If a
usage of 80% is achieved at each hierarchical level, then
the overall
usage will be (0.80 to the power of "n"). It is then possible to calculate HD ratio values from this value.
Size range Level Utilisation HD ratio (prefix) (n) (0.80**n) (calculated) /24 to /20 1 80%
.960 to .973
/20 to /16 1.5 72%
.961 to .970
/16 to /12 2 64%
.960 to .968
/12 to /8 2.5 57.2%
.960 to .966
/8 to /4 3 51.20%
.960 to .966
The levels of hierarchy listed above are based on assumptions about the likely size and structure of LIRs holding
address blocks of
these sizes. A reasonable HD ratio value may be 0.96 (a
round figure
which occurs within most of these ranges) from the table
above. The
following table gives the usage requirements for IPv4
address blocks
from /24 to /8 for this value.
IPv4 Addresses Addresses
Util%
prefix total used 24 256
205
80.11% 23 512 399
77.92%
22 1024 776
75.79%
21 2048 1510
73.71%
20 4096 2937
71.70%
19 8192 5713
69.74%
18 16384 11113
67.83%
17 32768 21619
65.98%
16 65536 42055
64.17%
15 131072 81811
62.42%
14 262144 159147
60.71%
13 524288 309590
59.05%
12 1048576 602249
57.43%
11 2097152 1171560
55.86%
10 4194304 2279048
54.34%
9 8388608 4433455
52.85%
8 16777216 8624444
51.41%
Note: This table provides values for CIDR blocks, but the same calculations can be made for non-CIDR blocks.
As an example, an LIR holding a total amount of address
space equal
to a /16 would be able to receive more address space when they had sub-allocated or assigned 64.17% of that space; while an
LIR holding
a /9 would be able to receive more space when they had
sub-allocated
or assigned 52.85% of their address space.
Appendix C. References [RFC 3194] "The Host-Density ratio for address assignment
efficiency: An
update on the H ratio", A. Durand, C.Huitema, November 2001. [ipv6-address-policy] RIPE NCC document: "IPv6 Address
Allocation and
Assignment Policy"
[ipv4-address-policy] RIPE NCC document: "IPv4 Address
Allocation and
Assignment Policies for the RIPE NCC Service Region" http://www.ripe.net/ripe/docs/ipv4-policies.html
Hi Hans, I agree with karsten, and do NOT support this policy change. Why: Conservation of v4 space is a greater priority for me than potentially easing V. large registries adminstrative overhead. In fact, I have never been convinced about this being a "problem" in the first place. In terms of hierarchy, as long as your v4 sub-allocation or assignment is in the RIPE Db, it is considered in use and counts as part of the 80%. -- Cheers, McTim nic-hdl: TMCG
participants (3)
-
Hans Petter Holen -
Koepp, Karsten -
McTim