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Community Member

From looking at the EIGRP topology table, what is the approach to find out which networks is a given router connected to ?

For example, imagine I want to find out which networks is the router at 173.17.10.2 directly connected to ? What should I consider when looking into that information in the show EIGRP topology table shown below ?

Initially I thought it was by looking at the 'connected' information, but then the answer from the book contradicts this approach. According to the book, the correct answer is that router 173.17.10.2 is directly connected to 3 networks:

173.17.2.0/24

173.17.3.128/25

192.168.0.0/24

Any idea what is the rationale used on this ?

P 173.17.3.128/25, 2 successors, FD is 30721, serno 9

via 173.17.10.2 (30721/28160), FastEthernet0/1

via 173.17.3.2 (30721/28160), FastEthernet0/3

P 192.168.0.0/24, 1 successors, FD is 156160, serno 16

via 173.17.0.2 (156160/120256), Fa0/0

via 173.17.10.2 (158720/156160), Fa0/1

P 173.17.10.0/24, 1 successors, FD is 20514560, serno 15

via Connected, Fa0/1

P 173.17.0.0/30, 1 successors, FD is 20514560, serno 15

via 182.16.1.1 (201514560/20512000), Fa0/2

via 173.17.10.2 (201518120/204514560), Fa0/1

P 173.17.1.0/24, 1 successors, FD is 30721, serno 8

via 173.17.10.2 (30721/28160), Fa0/1

via 173.17.3.2 (33280/30721), Fa0/3

P 173.17.3.0/24, 1 sucessors, FD is 28160, serno 3

via Connected, Fa0/3

Community Member

The best way to check which are directly connected networks for the router 173.17.10.2

is to look at the topology table on that router instead.

This table is of a router that is on the same subnet as the one in question.

To confirm this you would see the router ID just after the command is input (its been omitted in this output though).

The 173.17.10.2 router is a successor to a few networks however that only means that it is the next hop or downstream neighbor. If its table does show the 3 networks are directly connected then the statement is true.

But I don't think you could be 100% sure they are directly connected by looking at another routers table.

HTH

Stu

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