Nah. IPv6 didn&#x27;t really start to get going until v4 exhaustion approached, so 20 years is an overestimate.<p>v4 will die when the routing table becomes too filtered and&#x2F;or the number of unreliable tunnels grows too large. You may remember how unpleasant v6 was around 2005 with all the flaky tunnels. v4 may well be like that by 2020 if address trading causes many long-prefix v4 routes.<p>Being yesterday&#x27;s technology <i>and</i> unreliable has a poor prognosis.