JNCIS-SP: Juniper Networks Certified Specialist – Service Provider Routing (2023) — Question 48

Which BGP attribute is used to detect routing loops?

Answer options

• A. AS path
• B. MED
• C. local preference
• D. next hop

Correct answer: A

Explanation

The AS path attribute lists all the Autonomous Systems a route has traversed, allowing BGP to identify and prevent routing loops by rejecting routes that contain its own AS number. The other options, such as MED, local preference, and next hop, serve different purposes in routing decisions and do not specifically function to detect loops.