TCP Port Test
A TCP port test tries to open a connection to one port on a host to see whether a service is listening there. This test reports the port as open, closed, or filtered by a firewall, with the connection time.
When to use this: A service such as SMTP on port 25, HTTPS, or a database is unreachable and you suspect a firewall. Command prefix tcp:
About the TCP Port Test
Test whether a TCP port on a host is open, closed or filtered, and how long the connection takes.
FAQ
- What is the difference between closed and filtered?
- Closed means the host answered and refused; filtered means nothing answered, usually a firewall dropping packets.
- Can I test port 25?
- Yes. ProbeKit’s server can reach port 25, which many home and cloud networks block.