Скачать или смотреть How to Get the Correct IP Address in Python Using Sockets

Learn how to retrieve the correct IP address in Python when dealing with multiple network adapters without disabling any connections.
---
This video is based on the question https://stackoverflow.com/q/64904625/ asked by the user 'Emel' ( https://stackoverflow.com/u/14271633/ ) and on the answer https://stackoverflow.com/a/64904892/ provided by the user 'Grismar' ( https://stackoverflow.com/u/4390160/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Getting the wrong IP in socket library (Python) - [Getting the information from another adapter]

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Understanding the Problem: Incorrect IP Address with Python Sockets

If you're working with network programming in Python, you may encounter situations where you need to retrieve the local IP address for your machine. However, you might find that the socket library returns the IP address of an unintended network adapter, particularly when you have multiple adapters installed, such as a VMware adapter in addition to your standard Wi-Fi or Ethernet connections.

In this guide, we'll look at how you can accurately obtain the correct IP address for your internet-connected interface, avoiding issues with unwanted network adapters.

The Issue at Hand

You may start with the following simple code to get your local IP address:

[[See Video to Reveal this Text or Code Snippet]]

This could yield a result like '192.168.160.1'. However, as you found when running ipconfig, this address belongs to a VMware Network Adapter, not your active Wi-Fi connection, which has a different IP—192.168.1.51. Disabling the VMware adapter allows you to get the correct IP, but it's not an ideal solution since it could interfere with your virtual machine functionality.

The Solution: Using a Datagram Socket to Get the Active IP Address

Instead of relying on socket.gethostname(), we can use a more reliable method to fetch the correct IP. The following code snippet illustrates how to establish a UDP connection to a well-known external address (such as Google’s primary DNS server) to get the IP address of the active interface that's used for internet connectivity:

Step-by-step Implementation

Import the socket module

Begin by importing the socket library, which contains the necessary functions for dealing with network connections:

[[See Video to Reveal this Text or Code Snippet]]

Create a Datagram Socket

This socket type is ideal for sending and receiving UDP packets. The UDP connection helps determine the active interface since it is often associated with external connections.

[[See Video to Reveal this Text or Code Snippet]]

Connect to a Reliable External Address

Connect the socket to a well-known server. Google’s DNS server at 8.8.8.8 is one of the most reliable options:

[[See Video to Reveal this Text or Code Snippet]]

Retrieve the Active IP Address

Now you can retrieve the active IP address of the socket using the getsockname() method:

[[See Video to Reveal this Text or Code Snippet]]

Close the Socket

It’s good practice to close the socket connection once you're done with your operations:

[[See Video to Reveal this Text or Code Snippet]]

Complete Code Example

Here's the entire code snippet put together:

[[See Video to Reveal this Text or Code Snippet]]

Important Considerations

Active Internet Connection: This method requires that you have an active internet connection. If you are on a network that doesn’t connect to the internet (for instance, a closed office network), you may want to connect to another reachable address, like your router's IP.

Service Availability: Ensure that the external service you connect to is up and accepting connections. Using Google DNS is generally reliable, but other services may not provide consistency.

Conclusion

By utilizing a UDP datagram socket to connect to an external IP address, you can reliably retrieve the correct IP for your active network adapter without needing to disable other connections. This approach is simple yet effective and can save you from unexpected issues when working with multiple network interfaces.

Now that you know how to accurately retrieve your IP address in Python, you can improve your network programming projects without the hassle of network adapter conflicts.