Define areas, prepare an addressing plan for the routers (including defining the NETs), and determine interfaces that will run Integrated IS-IS.
Enable IS-IS as an IP routing protocol on the routers, and assign a tag to the process (if required).
Configure the NETs on the routers. This identifies the routers for IS-IS.
Enable Integrated IS-IS on the proper interfaces on the routers. Do not forget interfaces to stub IP networks, such as loopback interfaces (although there will not be any CLNS neighbors on these interfaces).
ISO has developed standards for two types of routing protocols:
● ES-IS discovery protocol— ES-IS performs “routing” between End Systems and Intermediate Systems referred as Level 0 “routing.” ES-IS is analogous to the Address Resolution Protocol (ARP) in IP. Although it is not explicitly a routing protocol, ES-IS is included here because it is commonly used with routing protocols to provide end-to-end data movement through an internetwork.
● IS-IS routing protocols— IS-IS performs hierarchical (Level 1, Level 2, and Level 3) routing between intermediate systems. Level 3 routing is done between separate domains. However, note that the IS-IS routing protocol is not itself capable of Level 3 routing. There is no Address Resolution Protocol (ARP), Internet Control Message Protocol (ICMP) or Inter-domain Routing Protocol (IDRP) for CLNS, but End System-to-Intermediate System (ES-IS) Protocol provides the same kind of reporting functions for ISs and ESs.
Adam, Paul (2014-07-12). All-in-One CCIE V5 Written Exam Guide (Kindle Location 4264). . Kindle Edition.