Google Professional Cloud Network Engineer Question 675
Single answerGoogle Cloud PlatformYou are configuring a hybrid cloud setup between your on-premises network and Google Cloud using Cloud Router and Border Gateway Protocol (BGP). Your on-premises router advertises multiple routes to the Cloud Router. To ensure that traffic from Google Cloud prefers a specific route back to your on-premises network, what BGP attribute should you configure on the on-premises router?
- A
Multi-Exit Discriminator (MED)
- B
Autonomous System Number (ASN)
- C
Route aggregation
- D
Link-local address
Show answer and explanation
Correct answer: A
Explanation
The Multi-Exit Discriminator (MED) attribute in BGP is used to specify the preferred route for traffic entering an autonomous system. In this scenario, to ensure that traffic from Google Cloud prefers a specific route back to your on-premises network, you should configure the MED attribute on the on-premises router. Other options like ASN, route aggregation, and link-local addresses are either not relevant or do not directly affect route preference in this context.
- A. Correct.
MED is used to influence the preferred path for traffic entering an autonomous system. By configuring MED on the on-premises router, you can indicate the preferred route for traffic coming from Google Cloud.
- B. Incorrect.
ASN identifies the autonomous system but does not directly influence route preference for incoming traffic.
- C. Incorrect.
Route aggregation is used to summarize multiple routes into a single advertisement, reducing the size of routing tables. It does not directly affect route preference.
- D. Incorrect.
Link-local addresses are used for communication between directly connected devices in the same subnet. They are not relevant for influencing route preference in BGP.