1. Enhanced IGRP Operation

2. What Is in a Neighbor Table? p2r2 p2r2#show ip eigrp neighbors IP-EIGRP neighbors for process 400 H Address Interface Hold Uptime SRTT RTO Q Seq (sec) (ms) Cnt Num 1 172.68.2.2 To0 13 02:15:30 8 200 0 9 0 172.68.16.2 Se1 10 02:38:29 29 200 0 6

3. Discovering Routes I am router A, who is on the link? Hello A B 1

4. Discovering Routes Update Here is my routing information. I am router A, who is on the link? Hello A B 1 2 3

5. Discovering Routes Update Here is my routing information. I am router A, who is on the link? Hello A B 1 2 Thanks for the information! Ack 3 5

6. Discovering Routes Update Here is my routing information. I am router A, who is on the link? Hello A B 1 2 Thanks for the information! Ack Topology Table 3 4 5

7. Discovering Routes Update Here is my routing information. I am router A, who is on the link? Hello A B 1 2 Thanks for the information! Ack Here is my route information. Update Topology Table 3 4 5 6

8. Discovering Routes Update Here is my routing information. I am router A, who is on the link? Hello A B 1 2 Thanks for the information! Ack Here is my route information. Update Topology Table 3 4 5 Converged Thanks for the information! Ack 6

9. EIGRP uses a composite metric to pick the best path Choosing Routes IPX 19.2 T1 IPX AppleTalk IP AppleTalk IP AB D C

10. Choosing Routes (cont.) 7 DestinationAdvert. Dist. 7 7 H B 30 21 220 Topology Table Network 7 (10) (20) (100) (10) C E F G (1) Neighbor D 7 A D B H

11. Choosing Routes (cont.) 7 DestinationFeasible. Dist.Advert. Dist. 7 7 H B 4030 3121 230220 Topology Table Network 7 (10) (20) (100) (10) C E F G (1) Neighbor D 7 A D B H

12. Choosing Routes (cont.) B is current successor H is the feasible successor 7 DestinationFeasible. Dist.Advert. Dist. 7 7 H B 4030 3121 230220 Topology Table Network 7 (10) (20) (100) (10) C E F G (1) Routing Table Neighbor D 31 7 7 B A D B H Router A’s

13. Maintaining Routes Net 7 (10) (20) (100) (10) C E F G (1) DestinationFeasible Dist.Advert. Dist. 7 H4030 Topology Table NeighborState A A 1 D H B

14. Maintaining Routes Do you have feasible successor to network 7? Query Here is a successor to network 7. Reply Net 7 (10) (20) (100) (10) C E F G (1) DestinationFeasible Dist.Advert. Dist. 7 H4030 Topology Table NeighborState A A 1 2 D H B

15. Maintaining Routes (cont.) Do you have feasible successor to network 7? Query I have no route to network 7. Reply Do you have feasible successor to network 7? Query I have no route to network 7. Reply 3 ABC

16. Maintaining Routes (cont.) Do you have feasible successor to network 7? Query I have no route to network 7. Reply Do you have feasible successor to network 7? Query I have no route to network 7. Reply 3 DestinationAdvert. DistanceFeasible Dist. Topology Table Neighbor State 4 ABC