Node.js – How to check whether an open port is TCP or HTTP


Specifically, I have a Windows server (Windows 7), but the netstat -an command only shows whether ports are TCP or UDP. I thought these were the only kinds of ports, but node.js seems to distinguish between HTTP ports and TCP ports (example at bottom of linked page). I'm currently using node.js in a program that will run on my server, and it opens HTTP ports by default. These appear as TCP ports under netstat -an.

Is there a command line trick for distinguishing whether an open port on this server is HTTP or TCP? I make requests to my Information Technology office about ports that I need on this server, and they need to know whether these ports will be TCP, UDP, etc.

If necessary to use a remote client, I have a Mac that can do the job.

Best Solution

All HTTP traffic is transmitted over TCP Ports. I think what may be causing some confusion is that the first node.js example uses the http module and the second example uses the net module.

The http module is built on top of the net module (which handles the TCP layer underlying HTTP).

Refer to: nodejs - net or http module


Only one process can bind to a port. If you're having difficulties connecting, shut down any other applications that may be using the same port, such as your Java Hello World server. Run netstat -an to make sure you don't see the port listed that you're trying to listen on in you node.js TCP server (port 1337) in the example. If nothing is listening on the port, fire up your node.js TCP server and run netstat -an again to make sure it's actually listening on the intended port.

Another suggestion - temporarily turn off the software firewall then use the telnet client on the local server to attempt to connect to the port using the command telnet 1337 (replace 1337 with your port) from the command prompt. This will eliminate any network devices such as firewalls between the client (telnet in this case) and the server. If the screen goes blank, you've connected. If you get the message Could not open connection to the host, on port then it's still not listening on the TCP Port. If you can connect locally from Telnet but you cannot connect remotely then there is something blocking your connection.