How many IP addresses does AWS own?

February 26 2020

| tech |

I use AWS for personal and work projects, and I was curious tonight as I am spinning up VMs left and right, and allocating a new IP address to each of them (via ENIs): just how many IP addresses does AWS own?

So, like most people, I googled it (thinking DDG wouldn't have as solid an answer), and wouldn't you know it, I was right that Google did have an answer!

Okay, so AWS has 5 IP addresses. Terrific.

Actually, AWS publishes their list of IP ranges so we can calculate the answer to this question. First, I downloaded the official AWS JSON file.

Next, we just need to do a bit of bash parsing to get the IP network prefix, and then subtract that value from 32 to get the power of 2 exponent, which we can use to calculate the number of unique IP addresses matching that IP prefix.

                $ grep -o "/.*" ~/Downloads/ip-ranges.json | cut -d '/' -f 2 | cut -d '"' -f 1 > ~/vals.txt
                $ while read line; do echo "32 - $line" | bc; done < ~/vals.txt > ~/exp.txt
                $ head ~/exp.txt

After that, it's just a matter of raising 2 to each of those powers and summing the result. To do this, I used the Scala repl because I couldn't remember offhand how to declare awk variables.

                $ scala
                scala> val lines = io.Source.fromFile("/Users/fitz/exp.txt").getLines.toList
                scala> => math.pow(2, x.toLong).toLong).sum
                res0: Long = 98293797

So, there you have it! Amazon, or AWS at least, owns 98,293,797 IP addresses as of February 26th 2020. At first I thought that seemed kind of low, given that every VM that their customers spin up can receive a public IPv4 address if the customer wants. But, I guess even if Netflix spins up a million VMs or Fargate containers with ENIs, that would still only exhaust 1% of their IP address space. I'm not sure---maybe that is low? IPv6 to the rescue.

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