
Michael Holland
In lesson 6.6 "EC2 Metadata and User Data", the bootstrap script runs a curl command "curl http://169.254.169.254/latest/meta-data/public-ipv4 >> index.html" to query for the meta data about your instance.
It’s confusing to me that this data is stored at a fixed IP for both all instances. As the same IP works for me as for Ryan in the video.
Can anyone explain?
As ever, once I asked the question I managed to find the correct explanation myself. 169.254.169.254 is the link local address, an auto assigned address that is only valid for communication within the broadcast domain of the connected host. Full explanation is available here https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/instancedata-data-retrieval.html
I was wondering the same thing. Thank you for the response.