Systems and methods are provided for evaluation of communication paths through networks to determine whether communication is permitted across one or more internal network boundaries. The analysis may be used to determine whether a node in one isolated network (e.g., VPC, VPN, client on-premise network, etc.) is able to communicate with a node in another isolated network across region and/or segment boundaries. The automated analysis can allow users (e.g., network administrators) to see what high-level policies (e.g., Cloud WAN policies written in a declarative language) are interfering with or permitting communication between the nodes.