Answer-first summary for fast verification
Answer: Tag the BGP announcements with the local preference BGP community tags. Set the tag to high preference for the first data center. Set the tag to low preference for the second data center. Configure the second data center’s router to have a lower local preference for the direct AWS BGP advertisements than for the advertisement from the fist data center., Configure the Direct Connect gateway to prefer routing through the Direct Connect connection with the first data center. Configure the second data center’s router to have a lower local preference for the direct AWS BGP advertisements than for the advertisement from the first data center.
The question revolves around ensuring traffic is routed through the first Direct Connect connection under normal circumstances, with the second connection serving as a failover. This requires manipulating BGP attributes to influence path selection. Option A suggests prepending the private ASN on BGP announcements from the second data center to make those paths less preferable, which is a common method to influence BGP path selection. However, it does not directly address the need for failover. Option B proposes using local preference BGP community tags to set a higher preference for the first data center and a lower preference for the second, which directly influences the path selection in a way that meets the requirement. Option C involves configuring the Direct Connect gateway to prefer the first connection and setting a lower local preference on the second data center's router, which also meets the requirement by ensuring the first connection is preferred and the second is used as failover. Option D's approach of using BGP community tags and AS_PATH prepends does not clearly address the failover requirement. Therefore, the correct solutions are those that directly influence path selection to prefer the first connection under normal conditions and use the second as failover, which are options B and C.
Author: LeetQuiz Editorial Team
Ultimate access to all questions.
No comments yet.
A company operates two data centers interconnected with multiple redundant links from different providers, using IP addresses within the 172.16.0.0/16 CIDR block. They run iBGP between the data centers with a private ASN and IGP. The company is transitioning to a hybrid setup, starting with one VPC in AWS. A Direct Connect connection from the first data center to a Direct Connect gateway is established using a private VIF, advertising a summarized route for 172.16.0.0/16. They plan to set up a second summarized route from the second data center to a different Direct Connect location. The company requires a solution to route traffic to and from AWS through the first Direct Connect connection, using the second connection solely for failover. What solution meets these requirements?
A
Prepend the private ASN on the BGP announcements to AWS from the second data center. Add a second VIF in the first Direct Connect connection. Advertise the same network without any prepends from the first data center. Implement the same setup for the BGP announcement from AWS to the two data centers.
B
Tag the BGP announcements with the local preference BGP community tags. Set the tag to high preference for the first data center. Set the tag to low preference for the second data center. Configure the second data center’s router to have a lower local preference for the direct AWS BGP advertisements than for the advertisement from the fist data center.
C
Configure the Direct Connect gateway to prefer routing through the Direct Connect connection with the first data center. Configure the second data center’s router to have a lower local preference for the direct AWS BGP advertisements than for the advertisement from the first data center.
D
Configure the focal AWS Region BGP community tag on the BGP route that is advertised from the fist data center. Configure AS_PATH prepends on the BGP announcements from the second data center.