BGP Interview Questions

A list of potential BGP (Border Gateway Protocol) interview questions that cover various aspects of BGP

• What is BGP (Border Gateway Protocol)? Explain its primary function.
• How does BGP differ from interior gateway protocols like OSPF and RIP?
• What are the main features and benefits of using BGP in a network?
• Describe the differences between eBGP and iBGP. When would you use each?
• What is an AS (Autonomous System) in the context of BGP?
• Explain the BGP neighbor establishment process.
• How does BGP determine the best path to reach a destination network? Discuss the BGP path selection algorithm (BGP best path selection process).
• What are BGP attributes? Name and briefly explain some common BGP attributes.
• How does BGP handle route advertisements and updates?
• What is BGP convergence? How does it differ from convergence in interior gateway protocols?
• Walk me through the basic steps to configure BGP on a router.
• How do you verify BGP neighbor relationships and routing information on a Cisco router?
• What are some common issues that can affect BGP neighbor relationships, and how would you troubleshoot them?
• Explain the concept of BGP route dampening. When is it used, and what problem does it solve?
• What are BGP communities? How are they used in BGP routing policy?
• What is route reflector in BGP? Why is it used, and how does it solve the full-mesh requirement in iBGP?
• Explain the concept of BGP Confederations. How do they address the limitations of route reflectors?
• Discuss the impact of BGP scaling issues and techniques to mitigate them.
• How does BGP support IPv6? What are the differences between IPv4 and IPv6 BGP configurations?
• Describe BGP security mechanisms and best practices to secure BGP sessions.
• You notice that BGP routes are fluctuating frequently between two routers. How would you troubleshoot this issue?
• You need to implement traffic engineering using BGP. What methods or techniques could you employ?
• How would you configure BGP to prefer routes from a specific neighbor over others?
• Your network is experiencing a DDoS attack targeting BGP. What measures can you take to mitigate this attack?
• Discuss the role of BGP in a multi-homed network. What considerations should you keep in mind when designing such a network?