Safe diagnostic scope
Limited every run to one host, explicit ports and a maximum 100-port range, with a clear authorization reminder.
Day 018 / Python / TCP Diagnostics
Port Probe Report
/ Overview
A dependency-free Python CLI that checks an explicit, bounded list of TCP ports and reports open, closed, timed-out or failed connections.
A failed connection does not always mean the same thing: the service may accept TCP connections, refuse them, time out behind a firewall, or fail because the host cannot be resolved. Ad-hoc checks also need firm scope limits.
/ Provided servicesClear thinking.
Clear thinking.
Practical delivery.
Honest failure classification
Distinguished accepted, refused, timed-out and operating-system errors instead of reducing every failure to a misleading closed state.
Automation-ready output
Produced stable terminal and JSON reports with useful exit codes while injecting network dependencies for deterministic tests.
/ Solution
Port Probe Report validates one authorized host and at most 100 explicit TCP ports, applies a per-port timeout, and classifies every result as open, closed, timeout or error. It reports known service names and connection latency in readable text or JSON without attempting vulnerability discovery or UDP scanning.
/ Impact
Four explicit connection states
Bounded checks of up to 100 ports
Readable and JSON reports
Eight deterministic network-free tests
Python standard library
socket, argparse, dataclasses, time and json provide the complete dependency-free utility.
TCP diagnostics
Explicit connection attempts and timeouts provide a small first-pass reachability report without vulnerability scanning.
Unittest
Eight network-free tests cover parsing, bounds, latency, refused connections, timeouts, operating-system errors and output consistency.