I have an API that I need to host in AWS that makes requests to an API that requires IP whitelisting. In other words every request I make from my AWS server/service must have the same IP, or an IP whitelisted range of IP addresses.

My current (incorrect strategy) is as follows:

Global Accelerator -> Application Load Balancer -> API Gateway -> Lambda

This doesn’t work because the Lambda does not have a static IP address, I’ve also had a hard time determining the range of IP’s from which the requests are emanating.

I believe I could setup an EC2 instance with a public static IP, but I was wondering if there is a better way of doing this. Our infrastructure team at my day job handles this in the banking sector so I know this is a solved problem, and I think it has something to do with NATed IP addresses BUT I’m just going to hand wave at this idea as I don’t understand it very well.

Any insight is greatly appreciated! Thank you for your time in reading/considering this!