Accessing a Web App on Ubuntu Internal Network (Port 7777)

A. Introduction

This article focuses on accessing a web application running on an Ubuntu machine with an internal network, specifically on port 7777. The steps to open the port and access the web app from the internal network are covered in detail.

B. Prerequisites

Before proceeding, ensure the following prerequisites are met:

• Ubuntu machine with a web application running on port 7777
• Access to the Ubuntu machine's terminal

C. Opening the Port

To open the port, use the following command:

This command grants incoming TCP traffic on port 7777.

D. Accessing the Web App

To access the web app from the internal network, perform the following steps:

1. Find the IP address of the Ubuntu machine using the command:
ip addr show
2. Identify the IPv4 address in the 'inet' section, which is usually the first one listed.
3. Use the IP address and port number to access the web app using a web browser. The URL should be in the format:
http://:7777

E. Troubleshooting

If you encounter issues accessing the web app, check the following:

• Ensure the Ubuntu firewall (ufw) is enabled using the command:
sudo ufw status
• Check if the web application is running and listening on port 7777 using the command:
netstat -anp | grep :7777

F. References

For further reading, consider the following resources:

• Ubuntu Server Guide: Firewall
• How do I set up a web server on Ubuntu?