200-301 Question 325
Single answerA network engineer is configuring a floating static route as a backup for an existing OSPF route. The primary OSPF route has an administrative distance of 110. Which configuration will ensure the static route is only used if the OSPF route fails?
- A
ip route 192.168.1.0 255.255.255.0 10.0.0.1 120
- B
ip route 192.168.1.0 255.255.255.0 10.0.0.1 90
- C
ip route 192.168.1.0 255.255.255.0 10.0.0.1 100
- D
ip route 192.168.1.0 255.255.255.0 10.0.0.1 110
Show answer and explanation
Correct answer: A
Explanation
A floating static route is configured with an administrative distance higher than the primary route's administrative distance to ensure it is only used as a backup. In this scenario, the OSPF route has an administrative distance of 110, so the static route must have an administrative distance greater than 110 (e.g., 120).
- A. Correct.
Correct. An administrative distance of 120 is higher than the OSPF route's administrative distance of 110, ensuring the static route is only used if the OSPF route fails.
- B. Incorrect.
Incorrect. An administrative distance of 90 is lower than OSPF's 110, so this static route would take precedence over the OSPF route, which is not the intended behavior.
- C. Incorrect.
Incorrect. An administrative distance of 100 is still lower than OSPF's 110, so this static route would take precedence over the OSPF route, which is not the intended behavior.
- D. Incorrect.
Incorrect. An administrative distance of 110 matches the OSPF route's administrative distance, which could lead to unpredictable route selection rather than ensuring the static route is used only as a backup.