The building-block objective is to reduce the vulnerability of Internet of Things (IoT) devices to botnets and other automated distributed threats, while limiting the utility of compromised IoT devices to malicious actors. The primary technical elements of this building block include network gateways/routers supporting wired and wireless network access, Manufacturer Usage Description (MUD) Specification controllers and file servers, Dynamic Host Configuration Protocol (DHCP) and update servers, threat signaling servers, personal computing devices, and business computing devices. The security capabilities of these components will not provide perfect security, but they will significantly increase the effort required by malicious actors to compromise and exploit IoT devices on a home or small-business network. The scenarios envisioned for this NCCoE building block emphasize home and small-business applications, where plug-and-play deployment is required. In one scenario, a home network includes IoT devices that interact with external systems to access secure updates and various cloud services, in addition to interacting with traditional personal computing devices. In a second scenario, a small retail business employs IoT devices for security, building management, and retail sales, as well as computing devices for business operations, while simultaneously allowing customers to access the Internet. This project will result in a freely available NIST Cybersecurity Practice Guide.