RIO Node-Red Listening on non-standard port


I have my device IO figured out on a RIO. Next step is getting TCP listener to work. The flow I am working on needs to listen on a specific port for a message. I am using ETH-0.

The application residing on another machine will simple open a connection to the RIO and send messages to it for the RIO to take actions.

When I deploy the TCP listener to listen to a port number less than 1024 I get a permission denied. I attempted to add a firewall rule on the RIO to for the subject port and interface.

This did not help. Higher port numbers do not give this error. Is this a hard restriction?

Learning as I go.


That’s a UNIX restriction: only applications running under the root user are allowed to bind to port numbers less than 1024. Node-RED doesn’t run as root, so it isn’t allowed to use those port numbers.

Oh that’s right, thanks Jonathan. The application I mentioned is a legacy software from an older system that I am working on phasing out. So I will work around it.


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Super slammed so late to the party… Check out the post here: