Recent technological progress has been materializing the Internet of Things (IoT), which is breathing new computational and communicational capability into anything in everyday life. An important step toward the IoT would be to facilitate suitable wireless sensor network technologies based on a verified standard protocol, the Internet Protocol, to support the network of things. An increase in research efforts has led to maturity in this field, yet there seem to be gaps to be filled because of the focus on how to adapt the IP to the space of things. This article introduces the Sensor Networks for an All-IP World (SNAIL) approach to the IoT. The proposed architecture includes a complete IP adaptation method. It also includes four significant network protocols: mobility, web enablement, time synchronization, and security. The feasibility and interoperability of the proposed approach is confirmed by the implementation of SNAIL platforms and tests on a testbed built in the Korea Advanced Research Network.