Hi, can someone explain this difference between this 1-12 steps order in case of internal/external metric
Each IS-IS router translates the information in the database into usable routes by implementing the Shortest Path First (SPF) algorithm. This computation is performed separately within each IS-IS level, and the results are compiled together and presented to the routing table on the router. The algorithm locates the metrically shortest path to each unique destination in the network. On occasion, the result of the calculation encounters multiple paths to the same destination learned through different means. To decide which path to use, the protocol has some tie-breaking rules to follow. The order of precedence for using a route is: 1. Level 1 intra-area routes with an internal metric 2. Level 1 external routes with an internal metric 3. Level 2 intra-area routes with an internal metric 4. Level 2 external routes with an internal metric 5. Inter-area routes (Level 1 to Level 2) with an internal metric 6. Inter-area external routes (Level 1 to Level 2) with an internal metric 7. Inter-area routes (Level 2 to Level 1) with an internal metric 8. Inter-area external routes (Level 2 to Level 1) with an internal metric 9. Level 1 external routes with an external metric 10. Level 2 external routes with an external metric 11. Inter-area external routes (Level 1 to Level 2) with an external metric 12. Inter-area external routes (Level 2 to Level 1) with an external metric Is it just meaning that ISIS protocol has two different preferences for each level: IS-IS Level 1 Internal Intermediate System to Intermediate System Level 1 internal routes 15 IS-IS Level 2 Internal Intermediate System to Intermediate System Level 2 internal routes 18 IS-IS Level 1 External Intermediate System to Intermediate System Level 1 external routes 160 IS-IS Level 2 External Intermediate System to Intermediate System Level 2 external routes 165 TIA! -- AA _______________________________________________ juniper-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/juniper-nsp
