Multiplexing traffic from multiple network namespaces to a single listener in a stream-based server application

Techniques of operating a server computer running an application for clients operating in multiple network namespaces involve multiplexing communications streams from clients hosted in different network namespaces into a single communication stream to present the requests to an application as if they originated from a single network namespace. Along these lines, a server computer commences operation by initiating a network namespace driver for each network namespaces and a multiplexing driver to multiplex network namespace communication streams received from the network namespace drivers. When the multiplexing driver receives an application access request from a network namespace driver within a network namespace communication stream, the multiplexing driver provides the request and a network namespace identifier identifying the network namespace driver to a stream head within a multiplexed communication stream that includes requests from other network namespace drivers.