Safety boundary: Use these instructions only for a router or network you own or are authorised to manage. Never enter a router password, Wi-Fi password, SSID, serial number or private network data into Router Portal.
Test one public port
Enter one authorised target and port. A result depends on a listening service and the probe method.
Result meanings
| Result | Usually means | Next step |
|---|---|---|
| Reachable | Expected response arrived | Confirm service and close rule later |
| Refused | Host responded, service rejected | Check listener/firewall |
| Timeout | No response before limit | Check NAT/CGNAT/filtering |
| UDP inconclusive | UDP may be silent | Use application-level test |
Safe use
A production probe needs controlled server-side checks, validation, rate limits, timeouts and minimal retention. This tool is not for port-range scanning or unauthorised reconnaissance.
1Authorised probe
↓
2Public host and port
↓
3Router/NAT
↓
4Local firewall
↓
5Listening application
Frequently asked questions
Does timeout prove closed?
No. Filtering, CGNAT or an offline service can also cause timeout.
Can I scan ranges?
No. The intended tool tests one authorised port.
Why is UDP inconclusive?
Many UDP services do not respond.