IS-IS

Link State


 * Dijkstra SPF Algorithm
 * "default" metric on interfaces (0...63)
 * Backbone Level (not area)
 * OSI Address: Area ID (value starting with 49 means private address) + System ID (6) + NSEL (1; default value is 00)
 * Databases: Level 1 = Intra-Area Routes; Level 2 = Backbone Routes

=Configuration=

Base
config# router sis config-router# net 49.0001.3333.3333.3333.00 config# interface s0/0 config-if# ip router isis

Levels
config-router# is-type [level-1|level-1-2|level-2-only]

Levels Per Interface with Metrics
config-if# isis circuit-type [level-1|level-1-2|level-2-only] config-if# isis metric 10 (0...63; 10 is the default)

Route Summaries
config-router# summary-address 172.16.0.0 255.255.0.0 [level-1|level-1-2|level-2-only]

Redistribution Tip
Use a route map to specify only the interfaces running ISIS that are to be distributed using the "redistribute connected" command