Re: Making Use of 240/4 NetBlock Re: 202203161019.AYC

Hi, Mark:

  1. Re: Ur. Pt. 2) " So replace every CPE device, including … ": It is evident that you even did not glance at the EzIP Draft Abstract before commenting, but just relying on your recollection of the past 240/4 efforts. Please spend a minute or two on reading the EzIP Abstract. In particular, please look for a keyword “overlay”. Hint, this was not our invention. It was a concise characterization by an authoritative Internet figure. So, we imported it into our latest IETF draft update. Hopefully, this keyword will steer your opinion on EzIP.

I’ve read the draft. Your proposal appears to rely on a specific value in the IP option header to create your overlay. While that sounds good on paper, it’s operationally been best practice for at least the last decade (maybe longer) to drop any packet with an IP option set that you don’t explicitly want because a significant number of routers kick every packet with options to CPU, so any substantive traffic flow with options set could knock devices over. I can’t speak to the current state of router processing, but I’d bet dollars to donuts most of those filters are still in place.

So, assuming your proposal were to eventually become an adopted standard, before it could reliably work across the general internet :

  • Any device that still treated 240/4 differently would need to be updated to treat it like anything else.
  • Any existing filters that dropped packets with any IP option set would have to be modified to permit the ones you define for EzIP
  • At least some router software would have to have IP option handling adjusted in some way. ( At one point in the past, one big router vendor only allowed you to configure an ip-options filter based on the IANA defined values, not others. )

This is a LOT of work and time for an overlay.

Hi, Fred:

  1. " … you will need to replace the existing DNS and DHCP systems… ": I am glad that you have touched the next level of considerations. Operating an RAN with one 240/4 netblock, there will be more than enough IP addresses to assign to all client premises. So, the EzIP deployment will operate with static IP address disciplines, negating the fundamental reasons to have DNS and DHCP. That is, transition to running the electronic equivalent of telephony White and Yellow Pages would be what EzIP deployment should rely upon.

  2. " … hear the relevant organizations saying that it changes their networking model, … similar to what has happened with the IPv6 deployment. ": Do they recognize that implementing EzIP address plan on CG-NAT changes no network model? So, the perturbation is far less than deploying IPv6.


Abe (2022-03-16 22:59)