CCNP EIGRP Components

EIGRP Tables
DUAL uses the EIGRP tables, which are provided. Within the EIGRP tables you will find a neighbor table, a topology table and a routing table.

Here are functions each table performs.
Neighbours Table - shows all neighbours adjacent to router
Topology Table - shows all route entries learned by the router
Routing Table – shows the best route to get to other points on the network


EIGRP Packets

Uses Five Packet Types

Hello
Check if the neighbor is up
Update
Used to send routing updates
Query
Finds out information from neighbors regarding routing updates
Reply
This is where the neighbors give a response
Acknowledgement
If you send a message, it must be acknowledged by the person who receives it. This packet is used to acknowledge a reliable packet.
The above are five main packets EIGRP uses. However, EIGRP can also use a packet called request.

Request – This packet is used to get information for a specific route. The information is received from one or more neighbors. Therefore the methods to send a request can either be through a unicast or a multicast process.




EIGRP Metric
EIGRP uses the metric component.
Metric is a Calculation done by the Routing protocol to determine the best path through a network. Since EIGRP uses 32 bits for its calculation it is metric is multiplied by 256. Metric consists of 5 components which are bandwidth, delay, reliability, loading, MTU.

EIGRP Metric Calculation
Metric = bandwidth + delay

EIGRP uses two of the components of metric which are bandwidth and delay. In the bandwidth, the measurement is based on the smallest amount of consumed data between the source and destination. In delay the delays in the path is measured.