ISIS

IS-IS

Link-state routing protocol
Uses Partical Route Calculation (PRC) for IP routes
Uses the DEFAULT metric on cisco routers (0-63)
Does not have a BACKBONE Area.Rather, a Backbone LEVEL
Requires a Single OSI ADDRESS

OSI Addressing
Hexadecimal
Composed of three parts
 -Area ID(Variable length)
 -Sytem ID(6 Bytes) --like a host address
 -NSEL(1 Byte) --like a service port
Read address from right to left because of Area ID(variable length)
49.003.1111.2222.3333.00
49.0152.3135.1AB2.FE00.63C9.00
49.005.1111.1111.1111.00
49 is a private address.

IS-IS routing maintains 2 IP Databases. 
  Level 1 Database: contains intra-area routes
  Level 2 Database: contains backbone routes
Routers may be L1, L2 or L1/L2.

Configuration
-trun on the routing process
-assign an OSI/NET address
-ip router isis -in each interface you want to run isis