Port Check
Test TCP port reachability against a target host.
What is Port Check?
A port check tests whether a TCP port on a host accepts connections from the internet path used by the checker — useful for firewall and service reachability triage.
How it works
PacketWizard attempts a TCP connect to the host and port you specify and reports whether the connection succeeded within the timeout window.
Common issues
Open locally, closed externally
NAT, cloud security groups, and ISP blocks often allow LAN access while denying public probes. Test from an external vantage point intentionally.
Filtered vs closed
Timeouts usually indicate filtering; immediate resets often mean nothing is listening. Interpret results with firewall policy in mind.
Frequently asked questions
Does a successful port check mean the service is healthy?
No. It only means something accepted the TCP connection. Follow with HTTP or TLS inspectors for application-level health.
Related tools
Continue with these related PacketWizard tools for adjacent diagnostics.