Migrate IP Addresses

The IP migration feature allows you to transfer the IP address of one application master to another application master. Typical use cases for this feature are:

  • When migrating from one environment to another.
  • When you want to attach an unattached IP address to an environment.

Note: Do not rely solely on this tool if you make use of (the none-default) Elastic Load Balancing functionality with a Classic or Application Load Balancer. The summary of instance types and count at the top of the Environment page will also list the number (if any) of Elastic Load Balancers in use. In addition to migrating the IP address, you will also need to either move the CLB, update the ALB Target Groups, or create a new ELB and swap your DNS in the case that VPC usages dictates that neither of the two options are available.


  • The two application masters must be in the same geographical region. IP addresses are region specific so they cannot be attached to an environment from a different region.
  • Stop all cron jobs before migrating the IP addresses.

Migrate IP addresses

To migrate an IP address:

  1. Log in to Engine Yard.
  2. Click Tools, then IP Addresses.
  3. Click the IP Migration Assistant button.
  4. In the Select Source Environment table, select the IP address from which you are swapping.
  5. In the Select Destination Environment table, select the destination environment.

    The geographical region of the source IP address and destination environment must be the same.

  6. Toggle the following options as necessary.

    Important: Engine Yard recommends enabling these configuration options. If you do not put the environments into maintenance mode while the IP address is being re-attached, user records could be mis-handled or application users could receive unfriendly error messages.

    • Enable Maintenance for Source Environment -- Enabling this option means that the source environment will be placed in maintenance mode during the swap IP process. When the swap IP process completes, the source environment will automatically be taken out of maintenance mode.
    • Enable Maintenance for Destination Environment -- Enabling this option means that the destination environment will be placed in maintenance mode during the swap IP process. When the swap IP process completes, the destination environment will automatically be taken out of maintenance mode.
    • Stay in Maintenance Mode on Error -- Enabling this option means that both the source and destination environments will stay in maintenance mode if the migrate IP process encounters an error. You will need to manually take the necessary environment(s) out of maintenance mode when you are ready.

    The default maintenance message is: This site is currently undergoing some maintenance.

    You can customize the message by updating the file located at /public/maintenance.html.

    Note: To manually take an environment out of maintenance mode, navigate to that environment and click Maintenance in the More Options area. See Use Application Maintenance Pages.

  7. Click the Migrate button.

    It can take up to 5 minutes for the IP address to get migrated to your new destination.

Note: For Solo environments, an environment-wide Apply is necessary to update the database.yml file. This is due to the hostname being pointed to the PHA (Public Host Address) instead of localhost. 

More information

These other resources might help you:

For more information about ... See ...
Upgrading to the new generation AWS instance families Upgrade Guide
Using application maintenance pages Use Application Maintenance Pages
How Engine Yard uses IP addresses About IP Addresses on Engine Yard Cloud

If you have feedback or questions about this page, add a comment below. If you need help, submit a ticket with Engine Yard Support.


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