This seems like the best course of action. Allocate 240/6 for private use as soon as practical and hold the rest of the E Class for private or public use as seems best later. Donald -----Original Message----- From: Daniel Senie [mailto:dts@xxxxxxxxx] Sent: Thursday, August 09, 2007 12:06 PM To: Marshall Eubanks Cc: ietf@xxxxxxxx Subject: Re: I-D ACTION:draft-wilson-class-e-00.txt ... If the IETF published an RFC that reassigned 240/4 to private address space usage today, it would likely be possible for enterprises to use it within a reasonably short period, perhaps a year or so, depending on how many vendors they work with, and their ability to assert pressure. Let's look at the reality of software stacks in the present time. Micorosoft updates desktops and servers weekly or more often, and people are fearful enough of security matters that they do apply them. Linux vendors similarly release patches quite often. Router vendors seem to have new software for one fix or another daily. If enterprises started working toward a deployment of pieces of 240/4, vendors would make it possible. A few of us looked at the Class-E issue some years ago, and thought it was worthwhile at that time to reclassify the space. Everyone understood it would take some time before the space was widely usable. If there's to be any use of the space, ever, a scenario that would get us to usability might be: - Reclassify Class-E space as usable address space - Enable a few pieces of 240/4 as private address space use. Let people start using that. - Enterprises, if there's interest will push vendors to make changes to stacks - In a few years, evaluate whether the space is viable for public assignment by ARIN, et. al. Even if the initial use of such space is limited to a few platforms and routers, it may be sufficiently useful to enterprises to use in private interconnects between companies, an area where significant difficulties are encountered today due to address re-use. There will of course be a chorus of responses that if changes are required anyway, folks should just migrate to IPv6. The counter-argument I'd make is simple: the changes required in IP stacks to enable Class-E as valid addressing is minimal, resulting in little new code, and thus little risk from untested code. Initially allowing blocks from this space as additional RFC1918-style space would provide a playground where enterprises, users and vendors could test their wares, without risk to the public Internet. For enterprises, the migration to IPv6 will be slow. The protocol stacks from all of the vendors are largely untested. I don't mean they haven't run code coverage, had QA teams and even interoperability testing. I mean there is limited experience with wide scale networks, high traffic volumes, exposure to denial of service and probing attacks. There will be vulnerabilites, just as there is with any code that's relatively new. As I believed several years ago, reclassifying 240/4 is worthwhile. Leveraging the need of enterprises for additional, sanctioned, private IPv4 space for interconnects may result in widescale implementation. Or it might not. The point is, it would be relatively simple to find out, and would not be overly distracting to the IETF or to efforts to migrate to IPv6 . _______________________________________________ Ietf@xxxxxxxx https://www1.ietf.org/mailman/listinfo/ietf _______________________________________________ Ietf@xxxxxxxx https://www1.ietf.org/mailman/listinfo/ietf