What does BGP MED typically control during the migration to GCP?

BGP MED, or Multi-Exit Discriminator, primarily influences traffic routing decisions on a network that employs Border Gateway Protocol (BGP). During a migration to Google Cloud Platform (GCP), BGP MED settings can help determine the preferred path for incoming traffic from different upstream providers or peer connections. By manipulating the MED value, a network engineer can signal which route they prefer for their data traffic, thus controlling how external peers interpret the available routes to their network.

When transitioning to GCP, adjusting BGP MED values can be crucial for optimizing the performance and redundancy of network traffic. It helps in steering the traffic through the most efficient route, which is essential for maintaining application performance during the migration process. Unlike other options, which address different networking aspects such as security, data management, or bandwidth considerations, BGP MED directly pertains to routing policy, making it the most relevant factor in this scenario.