What are the basic configuration steps to enable IS-IS?

A.
Configure the net system-id and the network net-id commands under routerisis.

B.
Configure the net system-id and the network net-id commands under routerisis and enable ISIS on each interface with the ip router isis command.

C.
Configure the network net-id command(s) and the is-type level-1-2 command under routerisis.

D.
Configure the network net-id command(s) under routerisis and enable IS-IS on each interface
with the ip router isis command.

E.
Configure the net system-id command under routerisis and enable IS-IS on each interface with
the ip router isis command.