[address-policy-wg] 2019-07 New Policy Proposal (Default assignment size for IXPs)

Hello,

On 22/10/19 18:24, Nick Hilliard wrote:
> INEX was a good internet citizen and started out with a /27 on our main
> peering LAN in 1996.  When that ran out, we moved to a /26 and then a
> /25.  We're now at /23.  For each renumbering operation, we ran into the
> problems above, and a lot more.  So from multiple experience, I wouldn't
> wish it on anyone to have to go through an IXP renumbering without good
> reason.  It really is a thorough pain, especially for the IXP participants.

Having gone through a renumbering exercise for an IXP myself (/22 to
/21) I can confirm that this is a painful process. But it is certainly
not an insurmountable challenge. Also, the smaller the IXP, the easier
it is. Fewer participants means less coordination.

The proposal already accommodates two years worth of growth, so it is
not like a renumbering exercise would be needed very often.

> The second issue is that there are ~220 IXPs operating in the countries
> in the ripe ncc region.  This number is pulled from IXPDB
> (https://api.ixpdb.net/v1/provider/list), and cross-referenced against
> the list of RIPE NCC countries here:
> 
> https://www.ripe.net/participate/member-support/list-of-members/list-of-country-codes-and-rirs
> 
> 
> A /15 has enough space for 512x/24 blocks, which means that this block
> will probably last indefinitely if the minimum assignment size is /24.

Possibly. But there is no guarantee that the growth in the number of
IXPs will remain the same. So being a bit conservative when there is
little downside seems wise to me.

I agree with James that the wording could be made a bit clearer.
Furthermore I think it should at least be possible to assign a /28 or a
/29 if an IXP requests this or if there are no larger blocks available.
But I don't think there's anything wrong with the /27 default, so I
support the proposed change in general.

Kind regards,
Martin