How to change host IP in flask

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by gayathrimohan dot icon Updated: Oct 10, 2023

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In Flask applications, a change_ip function is not a standard or built-in feature. But you might be referring to a custom function. 

We install this to change the IP address associated with a client request. A "change_ip" function deals with changing or managing these addresses.   

Let me explain how you can achieve this:  

  • Request IP Address: In Flask, you can retrieve the IP address of a client. You can make a request to your app using the request object. You can access the client's IP address using request.remote_addr.   
  • Changing IP Address: You can install your custom logic within your flask view for fun. It would help if you did this when you want to change the IP address before processing the request.   

We can categorize IP addresses into two main types.  

Here's a brief overview of each type:  

  • Static IP Addresses: Unless modified, devices assign static IPs that do not change.  
  • Dynamic IP Addresses: These are to devices by a DHCP server on the network.  

The change_ip function in a Flask app can do many things. It can access outside resources and handle user authentication. Here are some ways you can use it. 

Accessing External Resources:  

  • Web Scraping: You can use the change_ip function to change the IP address of your Flask app. We do this to avoid IP blocking when web scraping external websites.   
  • API Requests: To access external APIs with rate limiting, you can use change_ip. Users use this function to rotate IP addresses. It helps them keep making requests without hitting rate limits.  
  • Proxying: By changing the IP address, your Flask app can act as a proxy server. Clients use this server to access external resources. Enhancing privacy and bypassing geo-restrictions accomplish this.  

User Authentication Management:  

  • Security Enhancements: You can install IP-based authentication. You can also install traditional methods like username/password or tokens.   
  • Two-Factor Authentication (2FA): Use this function as a layer of security in 2FA.   
  • Access Control: Restrict or allow access to certain routes or sections of your Flask app. The system does this based on the client's IP address.  

Load Balancing and Failover:  

  • Load Balancing: This function can help as a load-balancing strategy. Users utilize this to distribute traffic across different servers. When the Flask app is part of a larger system with many instances, people do this.   
  • Failover: In case one server becomes unavailable. Then, changing the IP can redirect traffic to a backup server. We ensure high availability and fault tolerance.  

Geolocation-Based Services:  

  • Localized Content: The function can find the client's IP address. We use this to personalize content or services based on their location.   

Rate Limiting and Abuse Prevention:  

  • Rate Limiting: Install IP-based rate limiting to prevent abuse of your Flask API.   
  • Abuse Prevention: Detect and block suspicious IPs by changing the server's IP address. You can make it harder for attackers to target your application.  

The change_ip function uses parameters to change the IP address and port number. 

Such a function can pass these common parameters: 

  • new_ip_address: This specifies the new IP address. That is the address that the system should use for network communication. Must define the target destination for network requests.  
  • new_port: This is the port number that defines communication.   
  • Interface: A device has multiple network interfaces. You can choose which one to use. You should configure that interface with the new IP address and port.  
  • subnet_mask: This determines the range of IP addresses. The network considers those addresses as local. The user specifies the network segment to which the new IP address belongs.  
  • Gateway: It is the IP address of the network router. This router connects the local network to external, like the internet. It's crucial for routing traffic outside the local network.  
  • dns_server: DNS servers are responsible for translating domain names into IP addresses. You can specify DNS server IP addresses to use for name resolution.  
  • Protocol: This parameter might specify the communication protocol to use. Those protocols are TCP or UDP.  
  • Timeout: A timeout value can limit the duration of the IP address change process. If the process exceeds the specified timeout, it may be aborted.  
  • Authentication: If applicable, users might provide tokens for authentication. Also, it is applicable to allow the IP address change operation.  
  • callback_function: You can specify the callback_function to execute code. Once completed or encountering errors, this action changes the IP address.  

In Conclusion, the change_ip function is a versatile tool. Networking and system administration use that. This provides a streamlined way to change IP addresses while minimizing potential risks. Doing this makes it a crucial component in maintaining and securing modern CN.  

Fig: Preview of the output that you will get on running this code from your IDE.


In this solution we are using flask library in Python.


Follow the steps carefully to get the output easily.

  1. Download and Install the PyCharm Community Edition on your computer.
  2. Open the terminal and install the required libraries with the following commands.
  3. Create a new Python file on your IDE.
  4. Copy the snippet using the 'copy' button and paste it into your python file.
  5. Run the current file to generate the output.

I hope you found this useful.

I found this code snippet by searching for 'How to change host IP in flask' in Kandi. You can try any such use case!

Environment Tested

I tested this solution in the following versions. Be mindful of changes when working with other versions.

  1. PyCharm Community Edition 2022.3.1
  2. The solution is created in Python 3.11.1 Version
  3. flask 2.2.5 Version

Using this solution, we can able to change host IP in flask in Python using pip with simple steps. This process also facilities an easy way to use, hassle-free method to create a hands-on working version of code which would help us to change host IP in flask in Python.

Dependent Library

flaskby pallets

Python doticonstar image 63300 doticonVersion:2.2.5doticon
License: Permissive (BSD-3-Clause)

The Python micro framework for building web applications.


            flaskby pallets

            Python doticon star image 63300 doticonVersion:2.2.5doticon License: Permissive (BSD-3-Clause)

            The Python micro framework for building web applications.

                      You can search for any dependent library on Kandi like 'flask'.


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                      1. How can I use the Flask development server to change the external IP address?   

                      The server configuration determines the external IP address. Rather than something you can control within Flask itself. The designers made this server for local use, not for production.  

                      By default, Flask binds to '' (localhost), only accessible from your local machine.   

                      To make it accessible, you can set it to '' like this:   

                      if name == "__main__":   

            '', port=5000)   

                      But be cautious when using '' as the host. Any IP address can access your Flask app, which may pose a security risk.  

                      2. What is the process for changing a different port in the Flask development server?   

                      To change the port in a Flask development server, you can specify the desired port number. You run your Flask application to do this. By default, Flask runs on port 5000. Here's how you can change it:  

                      • Using the Command Line: Specify the port when running your Flask app from the command line. You can do this by using the -p or -port option. Flask run p 8080  
                      • In Your Python Script: You can also specify the port where you create the Flask app instance. Here's an example of how to set the port to 8080 in your Flask app code:  

                      from flask import Flask  

                      app = Flask(__name__)  

                      if name == "__main__":   


                      Either of these methods will allow you to change the port number for your Flask dev server to the desired value.  

                      3. Can I edit the Python file to enable changes in the Flask development server?   

                      You can edit a Python file to enable auto-reloading in the Flask development server. To do this, you must set the debug mode to True and specify the host and port. Here's how you can do it:  

                      • Locate the Python file containing your Flask app, often named  
                      • Find the section where you create your Flask app instance within that file. It looks something like this:  

                      app = Flask(__name__)  

                      • Add the following lines before running the app using the We do this to enable debugging and auto-reloading. 

                      if name == '__main__':   


                      Save your changes to the Python file.   

                      Now, when you run your Flask application using python The dev server will be in debug mode and reload whenever you change the code. You can see the results without restarting the server each time.  

                      4. Can the Flask development server connect remotely if I change the IP address and port?   

                      Yes, remote connections are possible with the Flask dev server. When running the server, you specify a host and port. You can change the host to '' to allow connections from any IP address and specify a different port if needed.   

                      For example:   

            '', port=8080)   

                      This will allow the Flask dev server to accept connections from remote devices. Use the server's IP address and the specified port to do this.  

                      See similar Kits and Libraries