An enterprise router receives routing updates for the identical destination network prefix (172.16.10.0/24) from two dynamic routing protocols: EIGRP and OSPF. Assuming default protocol settings and identical prefix lengths, which criterion determines which path the router places into its active IP routing table?
- Administrative distance, selecting EIGRP because its default value of 90 is lower than OSPF's default value of 110Answer
- BThe raw protocol metric value, selecting OSPF because its cost metric uses smaller integer numbers than EIGRP composite metric values
- CTransport layer protocol classification, prioritizing OSPF because it uses Layer 4 connectionless delivery
- DPort Address Translation mapping priority, selecting the path with configured public IP translation rules
Answer
Administrative distance determines the path installed in the routing table, choosing EIGRP because its default administrative distance of 90 is lower than OSPF's 110.
When multiple routing protocols advertise the identical destination prefix, the router uses Administrative Distance (AD) to assess source trustworthiness. Internal EIGRP has a default AD of 90, whereas OSPF has a default AD of 110. Because 90 is lower than 110, the router selects the EIGRP path for installation into the routing table.
Step-by-Step Solution
Key Concept
Administrative Distance vs Metric in Route Selection