Bulletproof : How likely are you to recover released EIPs?

AWS recently released the ability to recover accidentally lost Elastic IPs (EIPs). While this is an awesome feature, I would still love to be able to tag EIPs, which might save some of those accidents from happening. But accidents do happen. We thought it would be a good experiment to test out how many EIPs we could recover from one of our internal test accounts.

For this experiment we are going to allocate 21 EIPs in one AWS account in Sydney (ap-southeast-2), three for each time interval.

We will allocate all 21 IP addresses and hold them for one day. At the one day mark we will de-allocate all of them. At each time interval we will try and recover the allocated EIPs assigned to that time interval. If we succeed we will note it down and then de-allocate again and then try again at the next time interval. By assigning three EIPs to each time interval we are at least guaranteed to have that number potentially available to that interval. Any that make it through previous time intervals is a bonus.

We've chosen some arbitrary time intervals as follows:

• 1 hour
• 12 hours
• 24 hours
• 48 hours
• 1 week
• 2 weeks
• 1 month

This is by no means scientific and of course your mileage may vary, and don't take our results as the likelihood that you'll be able to recover your IPs.

First we need to increase the limit of allocated EIPs.

Stay tuned as we keep you up to date on our experiment.

Part 1 of our Testing the new EIP Recovery technical series.