Systems and methods for the management of virtual machine instances are provided. The hosted virtual machine networks are configured in a manner such that communications within the hosted virtual machine network are facilitated through a communication protocol. Illustrative embodiments of the systems and methods may be implemented on a virtual network overlaid on one or more intermediate physical networks that are used as a substrate network. Through the utilization of one or more virtual network mapping components in communication with the hosted virtual network components, communications to and from the hosted virtual networks can be processed by mapping relationships between the virtual network communication protocol and the router communication protocol. The mapping information can be provided in advance or as requested to the router components and hosted virtual network components to facilitate bi-lateral communications between the components.