Google Professional Cloud Network Engineer Question 678
Single answerGoogle Cloud PlatformYour company has deployed a hybrid cloud architecture using Google Cloud's Dedicated Interconnect to connect its on-premises data center to Google Cloud. You are configuring Border Gateway Protocol (BGP) to exchange routing information between the on-premises network and Google Virtual Private Cloud (VPC). The on-premises network administrator has requested that specific routes originating from the Google Cloud VPC are prioritized for traffic routing over others. Which BGP attribute should you configure to meet this requirement?
- A
AS Path
- B
Multi-Exit Discriminator (MED)
- C
Local Preference
- D
BGP Community
Show answer and explanation
Correct answer: B
Explanation
The Multi-Exit Discriminator (MED) BGP attribute is specifically used to influence inbound traffic by indicating which route should be preferred when multiple paths exist between two Autonomous Systems (AS). In this scenario, the requirement is to prioritize specific routes originating from the Google Cloud VPC. Configuring the MED value on the Google Cloud side will signal the on-premises router to prefer those routes.
- A. Incorrect.
AS Path is used to determine the preferred route based on the number of Autonomous Systems (AS) a route traverses. This does not allow explicit prioritization of specific routes within the same AS.
- B. Correct.
The Multi-Exit Discriminator (MED) is used to influence the inbound traffic by indicating the preferred path from one AS to another when multiple paths exist. It is the correct attribute to prioritize specific routes.
- C. Incorrect.
Local Preference is used to influence outbound traffic within an AS, ensuring that certain routes are preferred within the same AS. This does not apply to inbound traffic prioritization from a different AS.
- D. Incorrect.
BGP Community is a tagging mechanism to group routes. It is not directly used for prioritizing routes but can be used for applying policies to routes.