I am trying to understand the below paragraph.
“Sia Status (Stuck in Active): This is a bad one…it means that EIGRP has not received a reply to a query packet from one of the neighbors within the allowed time (about 3 minutes). When this happens, EIGRP will drop the neighbor adjacency, and it will be stuck in active. More on this later!”
Now my question is, If a network is unreachable in EIGRP then it will send a query packet to its neighbors. If the router does not receive any reply for that query then why would it drop its neighbor adjacency ???
The thing I struggled with is I assumed that this was the distance for each router to the destination. It is not about that. What this lesson is saying is that each of these routers is advertising a route with a certain feasible distance to R3 while following the split horizon rule. After all of that R3 looks at all of the routes for the destination that it has received from all of the routers and looks at the lowest feasible distance while following the feasibility condition.
one of the questions I had for a while was if split horizon blocks the interface on R1 from advertising wouldn’t it block it if we had 3 routers like this R1 → R2 → R3. It would not because split horizon just stops us from advertising a route out of the same interface it doesn’t stop us from receiving a route and adding our interface metric to it.
just wrote this just in case it helps anyone else.