Intro
Say you want to check if a tcp port is open from your standard-issue Windows 10 PC. Can you? Yes you can. I will share a way that requires the fewest keystrokes.
A use case
We wanted to know if an issue with a network drive mapping was a network issue. The suggestion is to connect to port 445 on the remote server.
How to do it
From a CMD prompt
> powershell
> test-netconnection 192.168.20.250 -port 445
ComputerName : 192.168.20.250.250
RemoteAddress : 192.168.20.250
RemotePort : 445
InterfaceAlias : Ethernet 3
SourceAddress : 192.168.1.101
TcpTestSucceeded : True
That’s for the working case. If it can’t establish the connection it will take awhile and the last line will be False.
What you can type to minimize keystrokes is
test-n <TAB> in place of test-netconnection. It will be expanded to the full thing.
Conclusion
On linux you have tools like nc (netcat), nmap, scapy and even telnet, that we network engineers have used for ages. On Windows the options may be more limited, but this is one good way to know of. In the past I had written about portqry as a similar tool for Windows, but it requires an install. This test-netconnection needs nothing installed.
References and related