Google Professional Cloud Network Engineer Question 677
Single answerGoogle Cloud PlatformYou are configuring BGP between your on-premises network and a Google Cloud Virtual Private Cloud (VPC) using Cloud Router. To ensure that specific routes from your on-premises network are preferred over others when being propagated to Google Cloud, you decide to configure the appropriate BGP attribute. Which BGP attribute should you configure?
- A
AS Path Prepending
- B
Multi-Exit Discriminator (MED)
- C
Local Preference
- D
BGP Community Tags
Show answer and explanation
Correct answer: B
Explanation
The Multi-Exit Discriminator (MED) attribute is used to assign a metric to routes, indicating the preferred route to use when multiple entry points are available. In this scenario, configuring MED will allow you to prioritize certain routes from your on-premises network when they are being propagated to Google Cloud via BGP. Other attributes like AS Path Prepending and Local Preference are not relevant for this use case.
- A. Incorrect.
AS Path Prepending is used to influence the route selection process by adding artificial hops to the AS path, making a route less preferred. It does not help prioritize specific routes as more preferred.
- B. Correct.
Multi-Exit Discriminator (MED) is used to indicate the preferred path into an autonomous system when multiple entry points exist. It is the appropriate attribute for prioritizing specific routes from your on-premises network to Google Cloud.
- C. Incorrect.
Local Preference is used internally within an autonomous system to prefer specific outbound paths. It does not impact route prioritization for routes being propagated to Google Cloud.
- D. Incorrect.
BGP Community Tags are used to group and identify routes for specific routing policies, but they are not directly used for prioritizing route preferences.