What is the use of the ip address 169.254.169.254 used in AWS? (43 of 285 technotes for 2015)

These are dynamically configured link-local addresses. They are only valid on a single network segment and are not to be routed.

Of particular note, 169.254.169.254 is used in Amazon EC2 and other cloud computing platforms to distribute metadata to cloud instances.

References:

• http://bit.ly/1HZZdpi
  
• http://amzn.to/1HZZoB8
  
• http://bit.ly/1HZZxnZ