Feasible Distance:
One of the metrics used to calculate the best path and it is the best cost path as determined by the “Local” router
Reported Distance:
Reported or Advertised Distance is a metric that is calculated by a remote neighbour in a remote network.
Nb. The route with the lowed FD is the route that will populate the EIGRP routing table.
Neighbour Table:
Stored in RAM, this table is a record of all adjacent neighbours address and interfaces. Each router will use this table to track the current state information of its neighbours
Topology Table:
This table records destinations as reachable by its neighbours or simply the topology of the network. Any changes will be triggered with partial updates
Routing Table:
Using the information found in the topology table, EIGRP will place the best routes into the routing table. known as successor routes, they provide the least cost to reach the remote network.
Feasible Successor:
An inferior alternate route to the successor, which is located in both the topology and routing table, whereas the feasible successor is only recorded inside the topology table. If the successor route was to fail this would be considered the backup route and take over.
It is good to note that in IOS 15.0 code you can keep upto 32 feasible successor routes in the topology table and previous codes upto 16.
Successor Route:
This is the best route to a remote network, and as mentioned previously it is recorded in both the routing and topology tables.