While the official master server was shut down due to legal actions, the community has maintained decentralized server lists and alternative launchers to keep the game active. Current Methods to Access the Server List
This paper provides a complete reference for developers, players, and server administrators working with the IW4x server list. iw4x server list
Green is good (under 80ms). Yellow is okay (80-120ms). Red is bad (150ms+). Always sort by ping first. A server with 250ms will ruin your hit detection. While the official master server was shut down