Policy: AWS > EC2 > Instance > Metadata Service

Instance metadata is data about your instance that you can use to configure or manage the running instance. Instance metadata is divided into categories, for example, host name, events, and security groups.

Instance metadata can be accessed from a running instance using one of the following methods:

* Instance Metadata Service Version 1 (IMDSv1) – a request/response method

* Instance Metadata Service Version 2 (IMDSv2) – a session-oriented method

By default, you can use either IMDSv1 or IMDSv2, or both. However, the instance metadata service can be specifically configured to use IMDSv2 on each instance. When you specify that IMDSv2 must be used, IMDSv1 no longer works.