AWS IAM Identity Center: Enabling Multi-Region Replication

For global enterprises, the resilience of access controls is non-negotiable. If your primary identity region goes down, can your team in another continent still access their critical AWS accounts? Until now, this was a single point of failure.

AWS has just announced Multi-Region Replication for IAM Identity Center. This feature allows you to replicate workforce identities and permission sets to additional regions. In this tutorial, we will set this up for GlobalTech Corp, a company headquartered in Northern Virginia (us-east-1) with a large engineering hub in Frankfurt (eu-central-1), ensuring their European team has low-latency, resilient access.

Step 1: Configure Multi-Region KMS Key

Before replication can start, encryption must be consistent across regions. You cannot use the default AWS-managed key. You must create a Multi-Region Customer Managed Key (CMK) in your primary region (us-east-1) and replicate it to your target region (eu-central-1).

# 1. Create a Multi-Region Key in Primary Region (us-east-1)
aws kms create-key --multi-region --description "IAM Identity Center Replication Key" --origin AWS_KMS

# 2. Get the Key ID and Amazon Resource Name (ARN) from the output...

# 3. Replicate this key to the target region (eu-central-1)
aws kms replicate-key --key-id  --replica-region eu-central-1

Ensure your IAM Identity Center instance permissions allow it to use this key for encryption/decryption in both regions.

Step 2: Enable Multi-Region Replication

Navigate to the IAM Identity Center console in your management account (us-east-1).

1. Go to Settings in the left navigation pane.
2. Select the Management tab.
3. Verify that the "Encryption" section is using your new Multi-Region KMS key.
4. Find the Regions section and click Add Region.
5. Select Europe (Frankfurt) eu-central-1 from the list.
6. Confirm the selection.

AWS will now begin replicating your Users, Groups, and Permission Sets. This process may take anywhere from a few minutes to an hour depending on the size of your directory.

Step 3: Update Identity Provider (IdP)

Replication creates a new Assertion Consumer Service (ACS) URL for the new region. You must add this to your IdP (e.g., Okta) so it knows it's valid to redirect users there.

• In IAM Identity Center console, click View ACS URLs.
• Copy the ACS URL for eu-central-1.
• Log in to your Okta/Entra ID Admin Console.
• Navigate to your AWS IAM Identity Center application settings.
• Add the new ACS URL to the specific configuration or "Bookmark App".

Step 4: Verification

Once setup is complete, simulate a login from your European hub.

1. User logs in via Okta and clicks "AWS Access - Europe".
2. They are redirected to the AWS Portal hosted in eu-central-1.
3. They click on an account (e.g., "Production - EU").
4. Access is granted using the locally replicated permission sets.

Even if us-east-1 goes offline entirely, this authentication flow remains active, ensuring business continuity for GlobalTech Corp.

Conclusion

AWS IAM Identity Center's multi-region support is a massive leap forward for enterprise resilience. By effectively using multi-region KMS keys and IdP routing, you ensure that your global workforce is never locked out of their infrastructure, regardless of regional outages.