Marty,
a bit less than 28,000 currently configured "Internet" network numbres believe they have permanently gained their class B's and C's. Or at least the ones in the US believe that.
a bit less than all assigned network numbers total believe that they have gained their class B's and C's and will never give up and renumber
You have provided no incentive (carrot) for individual companies to do the right thing.
Let us try to answer your question with another question: Do you want a routable large scale global Internet ? It is hard to imagine supporting a truly huge Internet without relying on hierarchical routing (CIDR is simply a realization of hierarchical routing). And if you do plan to rely on hierarchical routing, then you need to understand how to deal with the issue of containing address entropy (due to switching among providers) without renumbering. It seems naive and perhaps irresponsible to think about flat routing (based on network numbers). It should be a goal to make this renumbering simple. We'd like to suggest that folks with alternative proposals to CIDR should put their alternative proposals on a table and explain, among other things, how their proposals would be deployed and used and how these proposals would be better than CIDR. Hitting the right time frame turns out to count! When people got network numbers in the past they were getting addresses for the research Internet. It is important to understand that the research Internet was a great thing, but we are now working on the global public Internet and we desperately needed new routing and addressing systems. We should establish that we are in a transition from the research Internet to the global public Internet and we subsequently can not just use uncoordinated IP addresses and still have a workable system. This is not dissimilar to what happened when local phone exchanges started to get interconnected during the advent of long distance telephone services. There needs to be a globally coordinated address space to make this work. Reasoning by analogy with the phone system is a powerful argument. People change phone numbers all the time, they don't absolutely revolt because the phone system is so valuable. Some elect to get 700 numbers, but they *PAY* for this service. We suggest the following subjects be carefully considered: The old addresses of the research Internet need to be reorganized into the global public Internet addressing plan which is based on CIDR. Those addresses not currently globally routed will not be routed. These new customers of the Internet should get their addresses from their immediate providers. (This could be softened if there is a commitment by the customer to enter into the transition ASAP). This also would cover the case of provider switching under CIDR. Those addresses that are currently routed will *eventually* be migrated to CIDR allocations. This may take some time, on the order of years (2-5). We could look for the simple cases first (small/tiny sites). It is not fair to get people to renumber when they attach to the Internet when they see that people already attached are just sitting pretty. We need to be consistent in the application of standards and rules. Marty has brought up the subject of a carrot: The carrot is getting global Internet routing. The stick is not getting global Internet routing. It is a dull and boring argument, but it is the core of the debate. There is extreme value in what we are trying to build with the global public Internet, and we need to impress on the customer base that we need their help to make it possible to achieve our goals. We are not saying this is going to be easy, but it is rare that something worth having comes for free. Peter & Yakov P.S. The number of uncoordinated IP addresses is higher than 30K.