300-420 Question 99
Select 2An enterprise network is experiencing issues with Layer 2 loops in its campus network design. The network engineer decides to implement a loop-free technology to address these issues. Which of the following technologies can be used to eliminate Layer 2 loops while ensuring high availability and optimal forwarding paths in the network?
- A
Spanning Tree Protocol (STP)
- B
EtherChannel with Link Aggregation Control Protocol (LACP)
- C
Cisco FabricPath
- D
Shortest Path Bridging (SPB)
- E
Bidirectional Forwarding Detection (BFD)
Show answer and explanation
Correct answers: C, D
Explanation
Loop-free technologies like Cisco FabricPath and Shortest Path Bridging (SPB) are designed to eliminate Layer 2 loops while enabling efficient and scalable network designs. These technologies leverage advanced protocols to ensure all links are active and used, unlike traditional STP, which blocks redundant paths. Other options, such as EtherChannel with LACP or BFD, address different network challenges but are not specifically designed for loop-free Layer 2 operations.
- A. Incorrect.
Spanning Tree Protocol (STP) prevents loops by disabling redundant paths, but it does not offer a true loop-free topology as it blocks paths instead of optimizing forwarding.
- B. Incorrect.
EtherChannel with LACP aggregates links to increase bandwidth and redundancy but does not inherently eliminate Layer 2 loops across the network topology.
- C. Correct.
Cisco FabricPath is a loop-free technology using a Layer 2 multipath protocol based on IS-IS, providing an efficient and scalable loop-free topology.
- D. Correct.
Shortest Path Bridging (SPB) eliminates Layer 2 loops by using a link-state routing protocol, enabling all links to be active and used, ensuring an optimal forwarding path.
- E. Incorrect.
Bidirectional Forwarding Detection (BFD) is a protocol for detecting failures on forwarding paths but is not a loop-free technology specifically designed to address Layer 2 loops.