Question

A network engineer manages a large multi-Region global network built on multiple Transit Gateways registered in AWS Cloud WAN's predecessor tooling via AWS Network Manager. After a routing change, an application team reports that traffic from a VPC attached to the us-east-1 Transit Gateway cannot reach a VPC attached to the eu-west-1 Transit Gateway, even though a peering attachment exists. The engineer needs to determine, without generating live traffic, whether the Transit Gateway route tables on both ends have the correct routes and where the path breaks. Which AWS Network Manager capability should the engineer use?

Accepted Answer

Use Network Manager Route Analysis to compute the forward and return paths across the registered Transit Gateways and identify the route table hop where the path is missing a route

Answer

Enable Transit Gateway Flow Logs on both attachments and inspect the records for REJECT actions to locate the break

Answer

Run VPC Reachability Analyzer between the two VPC ENIs to trace the end-to-end path across Regions

Answer

Use the Network Manager global topology view and manually compare the two Transit Gateway route tables for missing entries