Respounder is a network detection tool that identifies active Responder tools within network environments through LLMNR query analysis. The tool operates by transmitting LLMNR (Link-Local Multicast Name Resolution) name resolution requests for non-existent hostnames across the network infrastructure. This methodology forces any deployed Responder instances to reveal their presence by responding to these fabricated queries. The application supports cross-platform deployment across 32-bit and 64-bit Linux distributions, OS X, and Windows operating systems. It can be implemented using pre-compiled binaries or compiled from source code using Golang without requiring additional dependencies. Respounder serves as a defensive security mechanism that enables network administrators and security professionals to detect potentially malicious Responder tools that could be utilized for credential harvesting or man-in-the-middle attack scenarios within their network perimeter.