LetMeThrough is a single-file, zero-dependency Python tool that goes beyond open/closed: it distinguishes refused (host alive, port not listening) from timed-out (network black hole) from local routing errors — with parallel scans across the full port range.
What it does
- Multi-layer diagnosis — refused vs. black-holed vs. local routing.
- Parallel full-range scans with configurable worker pools.
- Groups closed ports by range so open ports stand out.
- Pure standard library — one
server.py, no dependencies.
Why it mattersHonest network diagnosis — it tells you where the block actually is, not just that there is one.
Built with
Python (stdlib)concurrent.futuresSingle-file HTTP server