On Mar 22, 2010, at 10:27 PM, Mark Newton wrote: > > On 23/03/2010, at 3:43 PM, Owen DeLong wrote: >> >> With the smaller routing table afforded by IPv6, this will be less >> expensive. As a result, I suspect there will be more IPv6 small multihomers. >> That's generally a good thing. > > Puzzled: How does the IPv6 routing table get smaller? > Compared to IPv4? Because we don't do slow start, so, major providers won't be advertising 50-5,000 prefixes for a single autonomous system.
> There's currently social pressure against deaggregation, but given time > why do you think the same drivers that lead to v4 deaggregation won't also > lead to v6 deaggregation? > I think that the same drivers will apply, but, think of IPv6 as a Big 10->1 reset button on those drivers. Sure, in 30 years, we may be back to a 300,000 prefix table, but, in 30 years, a 300,000 prefix table will be well within the hardware capabilities instead of on the ragged edge we face today. > (small multihomers means more discontiguous blocks of PI space too, right?) > Yep. It does. However, IPv6 gives us a 30-50,000 prefix table now (when we get there) and 10-30 years to solve either the TCAM scaling issue or come up with a better routing paradigm. I think that eventually an ID/Locator split paradigm will emerge that is deployable. I think that SHIM6 and the others proposed so far are far too complex and end-host dependent to ever be deployable. Likely we will need to modify the packet header to be able to incorporate a locator in the header in the DFZ and do some translation at the edge. I haven't fully figured out the ideal solution, but, I think several others are working on it, too. Owen
