On 06/08/2012 23:02, Martin Rex wrote: > Steven Bellovin wrote: >> Randy Bush wrote: >>> whatever the number of address bits, if it is fixed, we always run out. >>> memory addressing has been a cliff many times. ip addressing. ... >> Yup. To quote Fred Brooks on memory address space: "Every successful >> computer architecture eventually runs out of address space" -- and I heard >> him say that in 1973. > > I'm wondering what resource shortage would have happened if IPv6 > had been massively adopted 10 years earlier, and whether we would have > seen the internet backbone routers suffer severely from the size > of the routing tables, if every single home customer (DSL subscriber) > would have required a provider-independent IPv6 network prefix rather > than a single, provider-dependent IPv4 IP Address. That was never a likely scenario (and still isn't). PA prefixes are still the norm for mass-market IP, regardless of version number. Brian