Techniques are described for providing managed computer networks. In some situations, the techniques include managing communications for computing nodes of a managed computer network by using one or more particular computing nodes of the managed computer network that are configured to operate as intermediate destinations to handle at least some communications that are sent by and/or directed to one or more other computing nodes of the managed computer network. For example, a manager module associated with a source computing node may select one or more particular intermediate destination computing nodes to use for one or more particular communications from the source computing node to an indicated final destination, such as based on a configured logical network topology for the managed computer network. The manager module then forwards those communications to a first of the selected intermediate destination computing nodes for further handling.