The other day I got a request from our team leader to check why our AWS expenses had shoot up unexpectedly the last month, after a few minutes revising the previous months billing I figured out that AWS started collecting taxes, cloudwatch has been increasing as we were implementing a better logging system for our apps, and also AWS started charing us $0.005 per IP address hourly starting on february 2024.

AWS New charges on IP Addresses

AWS IP Address cost per hour

In my mind I had a proposal to start removing IP Addresses but from previous experiences like this I learned that the best way to be taken serious is by showing the numbers. Investigating the case I found an amazing report called IPAM (Amazon VPC IP Address Manager), that helped me to detect all of the public /elastics IPs assigned to our services.

After setting the report, AWS took like 1 day or so to map all of the ip addresses in the account, also I had to set this several times as we had several accounts for environment isolation. In the meantime as I was curious about what could be the total number of addresses I started checking services manually, my count was around 50 IP addresses but the next day I was surprised by the IPAM report, there were 85 IP addresses in use and most of the were to services that didn’t require an IP Address. An example of this was the main database, deployed in a public subnet allowing public access to it, this was fixed and the DB is in the private subnet now, we will cover this in detail in another post.

Now it was time to show the numbers and a plan to start removing IPs, early that day I mentioned to the CTO the expenses associated to the IPs and at first this was kinda disregar until I showed the total IP addresses and the impact in costs yearly, it was near to 4.000, also my plan to remove them considered 2 or 3 workdays. You might guess at this point I got green light to start cleaning.

Total IPs Cost hour Total Hours (365 days) Total Yearly
85 $0.005 8,760 $3,723

This is how the IPAM report looks after the cleaning:

IP Address total after cleaning

Total IPs Cost hour Total Hours (365 days) Total Yearly
14 $0.005 8,760 $613.2

After removing all the unused ip addresses we were saving a bit over $3,100, and even more important, details about old non documented implementations were discovered and with that a great oportunity to improve our security, reliability, performance, cost savings and more.

This is proof of the importance of sustaining your findings when presenting this to the team leader or even to a board of directors, It’s a lot easier for people to get what you’re saying when you back it up with numbers and simple graphs, especially if they’re not super technical.