Milo, Since you raised the point about the Fuzzballs, I would also like to point out that the Merit PDP-11 operating system has had CIDR routing capabilities since 1985 or so. Obviously the wave of the future. On a more substantial note, one issue that was raised at the IETF concerned the idea of subnetting with CIDR (as opposed to supernetting). When do you think that the NIC(s) will be able to hand out pieces of what we now think of as class A nets, for example? My thought is that not only will a very large portion of the Internet need to be CIDR-ized before this happens, but several routers will need to have significant changes to the way forwarding works. Does anyone agree with this? Mark
From: "Milo S. Medin" (NASA ARC NSI Office) <medin@nsipo.nasa.gov> To: Vince Fuller <vaf@Valinor.Stanford.EDU> CC: Erik Sherk <sherk@sura.net>, regional-techs@merit.edu
I strongly agree. The issue of an "all-nets" broadcast is inconsistent with classless network routing. We should be taking steps to eliminate knowledge of class in all router and host implementations, as flexibility here will certainly be helpful in increasing the lifetime of the IPv4 protocol suite, and transitions from that suite. I always thought the "all nets" broadcast was a broken idea for many reasons, this being one of them.
OSPF was designed to be classless internally, but have defaults that are somewhat based on class boundaries. In general, it should be possible emulate "class" for human factors reasons if you implement everything in a truly classless way. Other routing protocols are making this transition as well. It's sort of back to the future, since I believe the original NSF backbone (56 Kbps fuzzballs which did a pure mask and match forwarding decision) had this capability!
Thanks, Milo