A network device receives, from a set-top box within a local network, a discovery request for a server application within the local network. The network device identifies, based on the discovery request, a wide area network (WAN) Internet Protocol (IP) address for a router in the local network and retrieves, from a database of multiple discovery records, a particular discovery record with an IP address that matches the WAN IP address for the local network. The network device sends, to the set-top box, the particular discovery record for use in initiating a communication session with the server application.