path tools
Port Checker
Port Checker tests whether TraceRoo can establish a TCP connection to a target host and port. It is useful for public services such as HTTPS, SMTP, SIP over TCP/TLS, and admin portals.
Common Ports
- 443 for HTTPS.
- 25, 465, and 587 for mail paths.
- 5060 and 5061 for SIP over TCP or TLS.
- Custom ports exposed by applications or firewalls.
When To Use It
Use it after firewall changes, DNS changes, service migrations, or when a provider says a public endpoint is unreachable.
Important Limits
- This checks TCP reachability, not UDP.
- An open port does not prove the application is healthy.
- A blocked result could be firewall policy, service downtime, or source filtering.
How To Read Results
- Reachable means TraceRoo could complete a TCP connection to the host and port.
- Timed out usually means no response came back before the test ended. Firewalls often look like timeouts.
- Connection refused usually means the host is reachable but nothing is listening on that port.
- DNS errors mean the hostname did not resolve before a port test could start.
- For TLS services, follow an open port with the certificate checker or header checker to confirm the application layer.
FAQ
Does Port Checker test UDP ports?
No. This tool checks TCP reachability. UDP services such as standard SIP over UDP need packet capture, SIP logs, or a protocol-aware test to confirm behavior.
Why does a port show open but the app still fails?
An open TCP port only proves the connection can be established. The application can still fail because of TLS, authentication, routing, host headers, protocol errors, or backend problems.
What does a closed or timed-out port mean?
It can mean the service is down, a firewall is blocking the connection, the port is wrong, DNS points to the wrong host, or the service only allows specific source IPs.