Every few months, the people who know the most about the Internet's architecture warn us that the Internet is doomed — address space is running out and we need to change to IPv6 as fast as we can. And other people call them Chicken Littles.
The best case for the version that says the sky is in fact going to fall isn't simply IPv4 number address space even though there's problems there — we keep inventing fixes of various degrees of ugliness that stave off the day of reckoning for that one, and there are huge allocated but unused blocks that could in theory be repurposed. No, The Internet's real Achilles Heel may be routers.
Router mapping tables keep growing, and there are signs that (despite clever enhancements) the BGP tables are getting up to capacity. And, we now hear the cost of routing all the traffic may be growing too quickly. Which means we may soon all be singing The Day The Routers Died:
Interesting post from Andrew Odlyzko about this on NANOG: Re: “ARPANet Co-Founder Predicts An Internet Crisis” (slashdot).
There are three things here: 1) v4 address space depletion, 2) BGP routing table depletion, and 3) link saturation. Predicting the first is like predicting an economic recession; it’s bound to show up eventually but it’s hard to predict when, and in the interim we’re getting a little tired of announcements that it’s coming. Or maybe it’s like global warming predictions (throw in the cost of mitigation plus the immaturity of the mitigations as disincentives to actually do anything about it). I don’t think link saturation is a serious problem; Larry’s been trying to figure out what to do about inefficient TCP congestion response for a long time, with a focus on changing the underlying transport (Cells In Frames, now this). The funny thing is that at some level what a lot of people want really is ATM; they just don’t want to call it that. But anyway, one way to get people to pay attention to his stuff is to announce a pending crisis, I guess.
The BGP problem is probably the most immediate, and switching to v6 isn’t going to help with that unless the shim6 stuff actually works and is actually adopted, and I haven’t been following it closely enough to have an opinion about that.
Larry Roberts also proposes that the Internet include “source address verification” as an essential security measure. This would have huge privacy implications, as tracing emails and web hits would become as easy for the authorities as for phone calls. Froomkin POV please.
Surely theres a bit of exaggeration about depleting IP address space and I believe this problem will be eventually solved this way or another (most probably by introducing IPv6).Nonetheless all that hype about the pending doomsday is of certain value as it clearly shows that the problem exists and something must be done about it.