▁support ▁IP v 6 ▁transport , ▁and ▁slowly ▁added ▁native ▁links ▁specifically ▁for ▁IP v 6 ▁transport . ▁ ▁Although ▁the ▁initial ▁ 6 bone ▁focus ▁was ▁on ▁testing ▁of ▁standards ▁and ▁implementations , ▁the ▁event ual ▁focus ▁became ▁more ▁on ▁testing ▁of ▁transition ▁and ▁oper ational ▁procedures , ▁as ▁well ▁as ▁actual ▁IP v 6 ▁network ▁usage . ▁ ▁The ▁ 6 bone ▁operated ▁under ▁the ▁IP v 6 ▁Test ing ▁Address ▁Al location ▁( see ▁ ▁), ▁which ▁specified ▁the ▁ 3 FF E :: / 1 6 ▁IP v 6 ▁prefix ▁for ▁ 6 bone ▁testing ▁purposes . ▁ ▁At ▁its ▁peak ▁in ▁mid - 2 0 0 3 , ▁over ▁ 1 5 0 ▁ 6 bone ▁top ▁level ▁ 3 FF E :: / 1 6 ▁network ▁prefix es ▁were ▁rout ed , ▁inter connect ing ▁over ▁ 1 0 0 0 ▁sites ▁in ▁more ▁than ▁ 5 0 ▁countries . ▁When ▁it ▁became ▁obvious ▁that ▁the ▁avail ability ▁of ▁IP v 6 ▁top ▁level ▁production ▁prefix es ▁was ▁assured , ▁and ▁that ▁commercial ▁and ▁private ▁IP v 6 ▁networks ▁were ▁being ▁operated ▁outside ▁the ▁ 6 bone ▁using ▁these ▁prefix es , ▁a ▁plan ▁was ▁developed ▁to ▁phase ▁out ▁the ▁ 6 bone ▁( see ▁). ▁ ▁The ▁phase out ▁plan ▁called ▁for ▁a ▁halt ▁to ▁new ▁ 6 bone ▁prefix ▁alloc ations ▁on ▁ 1 ▁January ▁ 2 0 0 4 ▁and ▁the ▁complete ▁c ess ation ▁of ▁ 6 bone ▁operation ▁and ▁routing ▁over ▁the