What is the best approach to troubleshoot connectivity issues between GKE clusters in different VPCs when you lack execution access?

Using the Network Connectivity Center to perform a Connectivity Test is the most effective approach to troubleshoot connectivity issues between GKE clusters in different VPCs, especially when execution access is not available. This tool allows for visual diagnostics of the network connectivity path without requiring direct access to the nodes or running commands directly.

What makes this approach particularly beneficial is its ability to highlight configuration errors and path issues in a user-friendly manner. It can provide detailed information about network status, route configurations, and potential disruptions in the data path between the clusters.

Other options may involve actions that require execution access or manual setup which could be impractical in the given scenario. For instance, installing a toolbox container would require administrative permissions and you may not be able to verify node configurations effectively without that access. Running the traceroute command, similarly, relies on having the ability to execute commands directly from the clusters, which is not an option here. Enabling VPC Flow Logs, while useful for monitoring, would involve a broader setup to catch and analyze traffic patterns and drops, instead of providing immediate insights into connectivity issues at that moment.

Thus, the use of the Network Connectivity Center for a Connectivity Test offers the most applicable and efficient solution under the constraints of limited access, making it the