350-401 Question 141
Select 3A network engineer is tasked with designing a network that includes both EIGRP and OSPF. The engineer needs to choose the appropriate protocol for different scenarios in the network. Which of the following statements accurately describe key differences between EIGRP and OSPF in terms of routing concepts and behavior?
- A
EIGRP supports unequal-cost load balancing natively, while OSPF does not.
- B
OSPF uses cost as its sole metric for path selection, whereas EIGRP uses a composite metric including bandwidth and delay.
- C
EIGRP requires the configuration of areas to scale efficiently, while OSPF can operate without areas in a flat topology.
- D
OSPF is a link-state protocol and relies on LSAs, while EIGRP is an advanced distance-vector protocol using DUAL for path computation.
- E
OSPF inherently supports unequal-cost load balancing, whereas EIGRP only supports equal-cost load balancing.
Show answer and explanation
Correct answers: A, B, D
Explanation
Understanding the key differences between EIGRP and OSPF is crucial for selecting the appropriate protocol in various network scenarios. EIGRP, being an advanced distance-vector protocol, uses the DUAL algorithm and supports unequal-cost load balancing. OSPF, a link-state protocol, uses LSAs for topology exchange and relies on a single cost metric for path selection. These characteristics make each protocol suitable for specific network designs and requirements.
- A. Correct.
Correct. EIGRP supports unequal-cost load balancing through the 'variance' command, a feature not natively available in OSPF.
- B. Correct.
Correct. OSPF uses cost (calculated based on interface bandwidth) as its sole metric, while EIGRP calculates its metric using a combination of bandwidth, delay, reliability, and load.
- C. Incorrect.
Incorrect. It is OSPF that requires areas (e.g., backbone area 0) for scaling in large networks, while EIGRP does not require areas and can operate in a flat topology.
- D. Correct.
Correct. OSPF is a link-state protocol utilizing link-state advertisements (LSAs) to exchange topology information, while EIGRP is an advanced distance-vector protocol using the Diffusing Update Algorithm (DUAL) to compute paths.
- E. Incorrect.
Incorrect. OSPF does not support unequal-cost load balancing, but EIGRP can achieve this with the 'variance' command.