ccnp route eigrp 1

EIGRP :
It is only routing protocol which keeps backup route.So it is extremely fast.
Combines best of distance vector and link state.
The only protocol which does unequal cost load balancing.
Every eigrp router maintains these tables:
-the neighbor table
-topology table==lists successor and feasible successor routes
-routing table==list the best route

Terms with EIGRP
Feasible Distance: how far from you to reach a particular network
Advertise Distance: how far it is from your neighbor to get to that network

To be considered a feasible successor, the AD must be less than the FD of the successor.
The reason behind this logic is used as loop prevention mechanism.

ACTIVE ROUTE:
This means the router is actively looking for a backup. There is something wrong with the network.

Passive route :
This means everything is working fine.

Eigrp Neighbor relationship
Hello: forms relationship
Update: send updates
Query: ask about routes
Reply: response to a query
ACK: Acknowledges the update, query, and reply messages

Eigrp uses multicast address as 224.0.0.10

Eigrp Metric calculation
Bandwidth (K1)
Delay (K3)
Reliability (K4 and K5)
Loading (K2)
MTU

Default Metric = 256 * (Slowest_BW + All_link_delays)
BW = 10^7/BW
Delay = Delay in microseconds