Implementing Cisco Enterprise Advanced Routing and Services (ENARSI) — Question 220

Which of the following correctly describes the concept of split horizon with IP routing? (Choose two.)

Answer options

• A. Split horizon is a valid routing loop prevention mechanism
• B. Split horizon is used to filter customer routes in an ISP network.
• C. When enabled, split horizons informs the router to not advertise routes back out the same interface from where that route was originally received.
• D. Split horizons cannot be disabled on WAN interfaces
• E. Split horizon is not applicable to EIGRP networks

Correct answer: A, C

Explanation

Answer A is correct as split horizon is indeed a valid mechanism to prevent routing loops by ensuring that routes are not sent back out the same interface. Answer C is also correct because it accurately describes how split horizon operates by preventing the advertisement of routes back through the interface they were learned on. The other options are incorrect as they either misrepresent the function of split horizon or state inaccurate limitations.