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