Change maximum delegation size of IPv4 address from 512 ( /23 ) to 768 (/23+/24) addresses. 
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Proposer: Aftab Siddiqui
aftab.siddiqui@gmail.com

Simon Sohel Baroi (sbaroi@gmail.com)


1. Problem statement
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According to the APNIC IPv4 Address Report,(https://www.apnic.net/manage-ip/ipv4-exhaustion/ ) the available 
and reserve pool size is as follows: 

Available Pool : IP Address 3,364,096 | 13,141 Of /24
Reserved Pool : IP Address 1,753,088 | 6,848 Of /24

If APNIC continues to delegate IPv4 in size of /23 with the average growth rate of 145 x /23 delegations per month the pool will be exhausted around Aug/Sep 2027. Which means the huge number of IPv4 addresses will be unused for a long time and large community members will still remain behind the NAT boxes.



2. Objective of policy change
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The current final /8 allocation policy [1] advise that the current minimum delegation size for IPv4 is 256 (/24) 
addresses and each APNIC account holder is only eligible to receive IPv4 address delegations totaling a maximum 
512 (/23) addresses from the APNIC 103/8 IPv4 address pool. (6.1. Minimum and maximum IPv4 delegations)

This is a proposal to change the maximum size of IPv4 address delegations from the available IPv4 address pool to 
a totaling of 768 (/23+/24) addresses. This proposal also indicates how APNIC will distribute the IPv4 resources 
systematically when the available pool size reduces.  

Increasing the maximum IPv4 delegation size from 512 ( /23 ) to 768 (/23+/24) address pool will allow Newcomers 
and also Existing APNIC account holders to get maximum number of IPv4 address resources.


3. Situation in other regions
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There is no similar policy in place in other RIR regions.



4. Proposed policy solution
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New APNIC Members are only eligible to receive IPv4 address delegations totalling a maximum 768 (/23+/24) from the APNIC available IPv4 address pool, provided the available+reserved pool is at Stage 1.

Existing APNIC account holders who are eligible (received IPv4 resources less than 768 IPv4 addresses) can apply for maximum delegation respectively maintaining the criteria matched with section 7.0.

If the available IPv4 Pool size, which consists of available and reserved pool, reaches 900,096 addresses (3516, /24s after last delegation), the delegation size will automatically become 512 (/23) IPv4 addresses i.e. Stage 2.

If the available IPv4 Pool size, which consists of available and reserved pool, reaches 256,000 IPv4 addresses (i.e. 1000 /24s after last delegation), the delegation size will be reduced to 256 (/24) IPv4 addresses I.e. Stage 3. The very first
time the reserved and available pool goes below 190,000 IPv4 addresses then, the IPv4 reserved pool of /16 (256 /24s) will be added to the available pool (APNIC-127 Section 5.1.1).

At any point, if APNIC receives a large block of recovered/returned/etc IPv4 address space increasing the total available address space and moved into the previous threshold then, the delegation size will revert back to previous delegation size as well. Also, all delegations at this stage have to be made retrospectively i.e. any member who received smaller delegation size will be eligible to receive more IPv4 addresses as per this policy, based on their usage criteria matched with section 7.0 and availability of addresses.

Whenever the next threshold is met then all resource requests received on the day and all those under review should be dealt with by the previous threshold.

Scenario 1: Today APNIC hostmasters are delegating according to Stage 1 delegation size limit (i.e. 768 IPv4 addresses) and there are 20 member applications in the queue. After delegating IPv4 addresses to applicant number 2 the threshold reached to enter Stage 2 (i.e. 512 IPv4 addresses) then at this stage all applications in the queue (i.e. 18 member applications) will be processed under Stage 1 criteria (i.e. 768 IPv4 addresses). Any new application (applicant number 21) will be processed under Stage 2. An existing member who only received /24 (i.e. 256 IPv4 addresses) during Stage 1 but later applies after APNIC enters into Stage 2 will only be able to request another /24 (totalling 512 IPv4 addresses).

Scenario 2: Today APNIC hostmasters are delegating according to Stage 2 delegation size limit (i.e. 512 IPv4 addresses) and there are 20 member applications in the queue. After a membership closure, APNIC received a /18 IPv4 address block which will bring them back to Stage 1 delegation size limit. All applications in the queue will be processed under the existing Stage 2 criteria (i.e. 512 IPv4 addresses). Any new application (applicant number 21) will be processed under Stage 1 and all those applicants who only received maximum delegation of /23 (i.e. 512 IPv4 addresses) will be eligible to apply for another /24 IPv4 address block. 


Threshold Stages for IPv4 addresses (Available + Reserved):

Stage 1 - More than 900,000 IPv4 addresses: Delegation Size /23 + /24
Stage 2 - Less than 900,000 IPv4 addresses and more than or equal to 256,000 IPv4 addresses: Delegation Size /23
Stage 3 - Less than 256,000 IPv4 addresses and more than 190,000 : Delegation Size /24
Stage 4 - Less than 190,000 IPv4 addresses add APNIC-127 5.1.1 Reserved /16 to available pool: Delegation Size /24


5. Advantages / Disadvantages
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Advantages:
Advantages:
This proposal will ensure smooth allocation of IPv4 addresses to existing and new APNIC members.



Disadvantages:
Disadvantages:
This might add up to 10,000 /24s into the global routing table i.e. 1.2% increase. The current growth rate without this policy is approximately 7% every year.



6. Impact on resource holders
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Existing APNIC members with less than 768 IPv4 addresses can also apply for maximum delegation.    



7. References
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[1] Section 6.1. "Minimum and maximum IPv4 delegations" of "Policies for IPv4 address 
space management in the Asia Pacific region" 
https://www.apnic.net/community/policy/resources#6.1.-Minimum-and-maximum-IPv4-delegations