EIGRP PART-3 (EIGRP Tables)

EIGRP Tables

EIGRP uses table to maintain its database. It builds 3 tables, they are:

1. Neighbor Table

2. Topology Table

3. Routing Table

1. Neighbor Table

As its name suggests this table consists of information of neighbor routers. Router collects this information from same AS by sending hello packets.

To show neighbor table

Router# show ip eigrp neighbor

H (handle) : It indicates that which neighbor adjacency is formed. The first router will have "0" the following one will have "1" and so on.

Address: IP address of the neighbor.

Interface: Interface that connects router to its neighbor.

Hold Time: It is a time that a router holds its neighbor if a hello is not received. 

Up time: It specifies the time since the neighbor is up.

SRTT: Smooth Round Trip Time, It shows the time taken for the packet to reach the neighbor and get an acknowledgement back.

RTO: Re-transmission Time Out, It show the time taken by a router to wait before re transmit a packet to the neighbor.

Q Cnt: Queue Count, It shows the number of packets that are waiting to be transmitted. Any number greater than 0, signifies some congestion in the network.

Seq Number:  It is the sequence number of the last packet received from neighbor.

2. Topology Table

Topology table stores every EIGRP route inside the autonomous system learned from neighbor routing tables. The topology table also holds the metrics for each of the listed EIGRP routes, the feasible successor and the successor.

To show neighbor table

Router# show ip eigrp topology

3. Routing Table

 This is the table that has the best possible route to a destination. 

To show routing table

Router# show ip route eigrp