Ralph, Where we ran into trouble the last time on this was that the OSS systems themselves that manage the edge devices needed to be able to actually communicate with those devices using the reserved space (reachability testing, what-have-you). All that stuff runs on a variety of h/w, including Linux, Windows, and other. But if ops want to use 240/4, I say have at it! It's just sitting there, after all... Eliot On 12/1/11 2:06 PM, Ralph Droms wrote: > On Dec 1, 2011, at 3:35 AM 12/1/11, Eliot Lear wrote: > >> Randy, >> >> >> On 11/30/11 6:09 AM, Randy Bush wrote: >>>> skype etc. will learn. This does prevent the breakage it just makes >>>> it more controlled. What's the bet Skype has a patched released >>>> within a week of this being made available? >>> cool. then, by that logic, let's use 240/4. the apps will patch within >>> a week. ok, maybe two. >> As someone who tried to "Go There", I agree with you that 240/4 is not >> usable. It would be fine in routers in short order, as it's fairly easy >> for ISPs to exert influence and get that code changed, but general >> purpose computing and all the OSS systems are a completely different >> kettle of fish. > Eliot - in the case of Shared CGN space, I think all that's needed is for the ISP routers between the CPEs and the CGN to forward 240.0.0.0/10 traffic. Those addresses will be hidden from the rest of the Internet by the CGN on one side and the subscriber GWs on the other side. If this address space weren't hidden, RFC 1918 space (e.g., 10.64.0.0/10) or a /10 reserved from public IPv4 space wouldn't work, either. > > Those subscriber GWs would have to handle 240.0.0.0/10 traffic correctly, and there would likely have to be some small amount of parallel RFC 1918 space in the ISP core network for servers, hosts, etc. Of course, I'm not an operator, so I'd be happy to hear why I'm confused. > > - Ralph > >> But that actually supports the notion that we need to use a different >> block of address space. So does the argument that 10/8 et al are well >> deployed within SPs. >> >> You wrote also that: >> >>> and all this is aside from the pnp, skype, ... and other breakage. >>> and, imiho, we can screw ipv4 life support. >> To keep this in the realm of the technical, perhaps you would say (a >> lot) more on how you think this would break IPv4? >> >> For the record, I'm of two minds- I hate the idea that the SPs haven't >> gotten farther along on transition, and I also wonder whether a rapider >> deployment of something like 6rd would be better than renumbering all >> edges into this space. On the other hand, that speaks nothing about all >> the content on v4 today, and that's where the pain point is. >> >> Thanks, >> >> Eliot >> _______________________________________________ >> Ietf mailing list >> Ietf@xxxxxxxx >> https://www.ietf.org/mailman/listinfo/ietf > _______________________________________________ Ietf mailing list Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf