Serverless Computing and Ephemeral IPs: The Servers That Don't Exist

Introduction: Code in the Void

Historically, to put code on the internet, you had to rent a server and give it a static IP address. Today, millions of websites use Serverless Computing (like AWS Lambda). In Serverless, your code just sits in a database until a user requests it. Then, AWS spins up a tiny, temporary server, runs the code, and instantly destroys the server 200 milliseconds later.

The Ephemeral IP

Because these servers only exist for a fraction of a second, they use **Ephemeral IPs**. They are born, assigned a random IP, and deleted almost instantly. This means you can't 'whitelist' a serverless function by its IP because it doesn't have a stable identity. You have to route them through an API Gateway to give them a permanent public face.

Conclusion

Serverless architecture forces us to forget everything we know about static infrastructure and embrace a fluid, on-demand networking model. Test your DNS resolution time here.