A strict firewall can block loopback traffic. While rare, it can happen. To test this hypothesis, temporarily disable your firewall and try to access localhost:11501 again. to ensure your system is protected.
(This outputs the Process ID (PID) utilizing the port. You can terminate it via task manager if needed). sudo lsof -i :11501 Use code with caution.
Understanding localhost:11501: A Guide to Local Development and Services localhost-11501
This is the standard hostname for your own computer. When you type "localhost" into a browser or application, the request is sent back to your own machine via a loopback address ) rather than going out to the internet. Port 11501:
If a process is listening, the issue may be a configuration mismatch. For instance, your application might be configured to listen only on the IPv6 loopback address [::1] , or a different address entirely. If it’s configured to listen on 0.0.0.0 (all interfaces), it will be reachable via localhost . Verify your application’s documentation or configuration file (e.g., a .env file or a config.js) to ensure it is binding to the correct host and port. A strict firewall can block loopback traffic
or
Simulators for smart home devices, industrial controllers, or custom hardware often expose a web‑based control panel or REST API on a specific port. Because these simulators are meant to run locally, they commonly use high‑numbered ports like 11501 . to ensure your system is protected
If you are seeing an error related to this address, it usually means the software that is supposed to be "listening" at Port 11501 isn't running. You can check what is currently using the port on your machine by opening a terminal and running: netstat -ano | findstr :11501 Mac/Linux: lsof -i :11501 Are you trying to start a specific server on this port, or did you encounter it in an error message What is localhost and how does 127.0.0.1 work? - IONOS