Express IP Filter Middleware

express-ip-filter-middleware is an Express.js middleware designed for robust access control, enabling developers to filter incoming requests based on IP addresses or CIDR blocks. It leverages Node.js's built-in `net.BlockList` for efficient management of allowed and denied IP ranges. The current stable version is 2.0.2, with recent releases primarily focusing on dependency updates, indicating an active maintenance cadence. Key differentiators include its explicit `whitelist` and `blacklist` modes, which mimic Apache's `mod_access` behavior, offering precise control over how allow and deny rules interact. It also provides an `ipOverride` option for custom IP address extraction, making it flexible for environments behind proxies or load balancers.