$76\mathrm{.}9\%$ complete

Question

In IPv$6,$ it is possible to configure addresses statically. However, most hosts obtain their global and link$-$local addresses from the local router. In IPv$6,$ the network and host portions are a fixed size. What is the network ID part of the IPv$6$ IP address $2001$:$0$db$8$:$0000$:$0000$:$0$abc:$0000$:def$0$:$1234?$