[address-policy-wg] 2023-01 New Policy Proposal (Reducing IXP IPv4 assignment default size to a /26)

Let me answer a few points with my co-author and "I work for an IXP" hat on:

> On 16. Jan 2023, at 11:09, Tore Anderson <tore at fud.no> wrote:
> 
>> 
>> I would rather see a policy that did not specify a default size at all,
>> but rather instructed the NCC to right-size each assignment according
>> to the "at least 50% utilisation after a year" rule. 

The /26 is a compromise between "make it useful" and "make it small enough".
Our idea was that new IXPs sometimes over-estimate their future success (-> "make the default small") and sometimes grow faster than expected (-> "jump directly to a /24"). But initially a /26 seems to be just right.

And we wanted a number in this policy. Otherwise too many "just give me a /24 because I am an IXP" requests, also if someone plans a new IXP they know what they get and can plan accordingly.

>> 
>> 
>> 
>> a) a new IXP can simply ask for an initial /25 and receive it, no
>> questions asked?

yes. But if a new IXP requests an initial /25 they at least have done some homework about what to expect. And I expect that homework to be shown to the RIPE NCC to get the /25.

>> b) an existing IXP that has used 50% of an initial /26 will be able to
>> upgrade straight to a /24, i.e., bypassing a /25? (Or even %50-of-
>> /27→/24, in an unlikely but not impossible corner case.)

Also yes. If the IXP grows really fast, they can go directly to a /24. Why? Renumbering an IXP is pain. A lot of pain. I  (personally) have run renumbering projects or participated in renumbering projects multiple times.

>> 
>> 
>> 2) Regarding «Assignments strictly larger than a /24 will only be made
>> to IXPs that offer the exchange of IPv4 routing information over IPv6
>> at their route servers»:
>> 
>> a) What is the purpose / meaning of the word «strictly» here? I assume
>> it is there for a reason, but removing it does not seem to me to change
>> the meaning of the sentence in any way (but then again, I am not a
>> native English speaker).

idea is:
strictly larger >
larger >=


>> 
>> b) Depending on whether one considers an assignment from the NCC to the
>> IXPs as to be a continuous state or as a one-time event, this may cause
>> an instant obligation on current holders of larger-than-/24 IXP
>> prefixes to implement IPv4-over-IPv6 routing in their route servers. Is
>> that the intention?

No, the policy only applies to new >/24 assignments 

> 
> 
> However, when we are at at a point in time where the IXP pool is
> completely empty except for such «space dust», why restrict the
> assignment size to /27? It seems to me that if we have reached a point
> in time where the only thing remaining in the IXP pool is «space dust»
> smaller than /27, and there is a small new IXP that could make use of,
> say, a /28, I see no reason to deny the IXP receiving that assignment.

IMHO a /28 is not useful for an IXP. Or what I consider to be an IXP. It allows for 14 IPv4 connections, so *if* that IXP does some monitoring and route servers, 11 IPs are free for customers. And no growth is possible.
We can do that once the pool is empty in another policy change IMHO.


best regards
Wolfgang
-- 
Wolfgang Tremmel                     

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