DUAL route FSM Processing of EIGRP Queries

Fig. 1: EIGRP route FSM

An interesting case of how DUAL route FSM operates.

First let’s note that an EIGRP router send a Query to its neighbor to find a better route to a destination that has passed from Passive to Active state; that is actively searching for a new feasible route to a destination that no more satisfies the Feasibility Condition.