EIGRP Terminology COPY Flashcards
Successor route
The route with the lowest path metric to reach a destination.
The successor route for R1 to reach 10.4.4.0/24 on R4 is R1 → R3 → R4
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Successor
The first next-hop router for the successor route.
The successor for 10.4.4.0 /24 is R3.
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Feasible Distance (FD)
The metric value for the lowest-metric path to reach a destination.
The feasible distance is calculated locally.
The FD calculated by R1 for the 10.4.4.0/24 network is 3328 (that is, 256+256+2816).
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Reported Distance
The distance reported by a router to reach a prefix.
The reported distance value is the feasible distance for the advertising router.
R3 advertises the 10.4.4.0/24 prefix with an RD of 3072.
R4 advertises the 10.4.4.0/24 to R1 and R2 with an RD of 2816.
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Feasibility condition
A condition under which, for a route to be considered a backup route, the reported distance received for that route must be less than the feasible distance calculated locally. This logic guarantees a loop-free path.
Feasible Successor
A route that satisfies the feasibility condition and is maintained as a backup route. The feasibility condition ensures that the backup route is loop free.
The route R1 → R4 is the feasible successor because the RD 2816 is lower than the FD 3328 for the R1 → R3 → R4 path.
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