Path Check for Mac

$ nc -vz example.com 443

What it’s for

Path Check answers a practical question: can this Mac reach that service right now? It shows the route macOS would use, then tries to connect to the host on each port you list, and reports what happened on each.

Use it when

• An app can’t connect to a server and you want to know whether the port is reachable.
• You want to check a few known ports quickly, without a full Port Scan.
• You’re checking whether a firewall or VPN is in the way.

Reading the result

Enter a host and the ports, or pick a set from Presets, then click Start Trace.

The Network section shows the system’s path: whether it’s Satisfied, the interface in use and the router (gateway). Each port then gets its own result:

• Reachable, with the time it took to connect. A service is listening.
• Refused: the host answered, but nothing listens on that port. The host is up.
• Unreachable or Timed out, with the reason: host not found, no route to host, or network down.

The summary sums it up, for example “Host reachable · 2/3 ports open”.

What you might see

• Couldn’t resolve the name. DNS can’t find the host. Check the spelling, or look it up in DNS Lookup.
• No port answered. The host may be down, or a firewall drops everything.
• No network connection. The Mac is offline, so no ports were probed.
• Every port to a device at home times out. Netutilus may need Local Network access. See Permissions & Privacy.

Options worth knowing

• Path Check takes a short list of ports. For a range, use Port Scan.
• The name is looked up once, before any port is tried.

Related

• Ports, what they are.
• A website won’t open.