On Apr 4, 2012, at 12:39 AM, Greg Daley wrote: > Renumbering in small organizations _is_ a big deal, especially when they don't have in-house skills to manage systems. I tried to look at that in RFC 4192. The question isn't whether it's a pain or not; it's what makes it painful. If building and deploying a protocol that will automagically renumber devices in a network will solve that, let's spruce up RFC 2894 and make it happen. In the discussions we had, it turned out to be that any automated service solved the easy 99% of the problem, whether it's done using DHCP, and fancy protocol, or a database back end. The real issues in renumbering aren't so much the process of distributing prefixes (IPv6 networks, route maps, ACLs, and so on) as much as dealing with broken software that makes silly assumptions about addresses - that an address that is meaningful to me is meaningful to you, that addresses once assigned never change, that a host or service has exactly one address, that given that knowledge one doesn't need to worry about names, and so on. Unfortunately, when one actively goes out of one's way to bypass anything that would allow us to automate the procedure, automated procedures can't help us. I agree that renumbering is a pain. I'm not certain what we could do in the protocol that fixes "stupid". That said, I'll put in a plug for RFC 6296, or for ILNP. ILNP would be a superior solution if I thought I could change TCP and UDP; I think RFC 6296 is a pragmatic step that is actually deployable (and deployed).