Enhanced IGRP Operation

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 To :15: Se :38:

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

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

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

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

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

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 Converged Thanks for the information! Ack 6

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

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

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

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

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

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

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

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