Which three statements about IS-IS are true? (Choose three.)

A.
IS-IS can be used only in the service provider network.

B.
IS-IS can be used to route both IP and CLNP.

C.
IS-IS has three different levels of authentication: interface level, process level, and domain
level.

D.
IS-IS is an IETF standard.

E.
IS-IS has the capability to provide address summarization between areas.