Described is a technology by which a server automatically configures itself for adding to an existing network. Upon connection to the network, the server obtains settings including existing subnet and gateway IP addresses from a DHCP assigned IP configuration (e.g., a router). The server uses the settings to automatically configure itself to dynamically provide addresses similar to the previous scope to clients. In one implementation, the server software sets its network card to a static IP address state while the server is configured, and thereafter sets the network card to a dynamic state. The router is disabled during server configuration, and re-enabled thereafter, whereby the server DHCP service instead of the router DHCP service assigns the addresses. The server may also attempt to automatically connect to the Internet.