200-301 Question 306
Single answerA network administrator is troubleshooting routing issues in a multi-protocol environment. The network uses both OSPF and EIGRP as routing protocols. The administrator notices that a particular route is being selected from EIGRP even though OSPF advertises the same route with a lower cost. What could be the reason for this behavior?
- A
OSPF has a lower administrative distance compared to EIGRP.
- B
EIGRP has a lower administrative distance compared to OSPF.
- C
The EIGRP route has a better bandwidth metric compared to the OSPF cost.
- D
The route from EIGRP is preferred because EIGRP operates as a link-state routing protocol.
Show answer and explanation
Correct answer: B
Explanation
When a route is advertised by multiple routing protocols, the administrative distance is used to determine which protocol's route is preferred. EIGRP has a lower administrative distance (90 for internal routes) than OSPF (110). Even if OSPF advertises a route with a lower cost, EIGRP's lower administrative distance causes its routes to be preferred.
- A. Incorrect.
Incorrect. While OSPF uses cost as its metric, it does not have a lower administrative distance compared to EIGRP. OSPF has an administrative distance of 110.
- B. Correct.
Correct. EIGRP has a lower administrative distance (90 for internal routes) compared to OSPF (110), which means EIGRP routes are preferred over OSPF when both advertise the same route.
- C. Incorrect.
Incorrect. While EIGRP uses bandwidth as part of its composite metric, the route preference is determined first by administrative distance, not the metric of the routing protocol.
- D. Incorrect.
Incorrect. EIGRP is not a link-state routing protocol; it is a hybrid routing protocol. This is unrelated to the route selection.