Cross forest mailbox migration - MRS Proxy - Can't connect

Question

Hello I have very simple environment. Trying to perform cross forest mailbox migration

Forest A - Source - 1 Exchange 2016
Forest B - Target - 1 Exchange 2016

Created send connectors
Created internal routing address @Source Technology .local, @target .local

Mail enable user in target
Ran the Prepare-MoveRequest.ps1 against the user target - Success.

Went to EAC to begin migration.

Receive the following error:

MRS Proxy is enabled on Source EWS directory
Basic Auth is enabled on EWS source directory

I put the FQDN of the source server as MRS proxy server. FQDN is resolvable. Firewalls are off

How do I troubleshoot this... It spins for 10-20 seconds before it errors out. What is it checking for? Is it looking for certificate that matches the FQDN I put as the MRS Proxy server? Event log shows nothing... how can I know what's going on?

Please help!

Answer 1

btw i found the issue - there's a bug if you enable the MRS Proxy via EAC ... they just released this... you have to enable via powershell to get it working. !!!

https://learn.microsoft.com/en-us/exchange/troubleshoot/move-mailboxes/remote-server-returned-error-403-forbidden

Answer 2

Hi @Chau Le

Since the detailed error message is 302 Too many automatic redirections were attempted,
Please open IIS manager on the target Exchange server and check if there are some HTTP redirecting settings on the Default Web Site or on the EWS virtual directory.

Example:
configured HTTP redirect to OWA in EWS :

Test-MigrationServerAvailability from another forest returns this error:

If any, please remove the redirecting settings and restart IIS to see if the issue persists.

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Answer 3

Hi @Chau Le

Glad to hear the issue has been resolved.
Thanks for your sharing.

While due to the policy of Microsoft Q&A forum, the question author cannot accept their own answer. They can only accept answers by others.

I have written a summary on this issue.
Please feel free to accept it as the answer to close this thread.
Thanks for your understanding.

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Issue Symptom:
The following error message appears when using EAC to perform cross-forest mailbox migration:

MRS Proxy and Basic Autn have been enabled on EWS source directory.

Workaround:
use Exchange Management Shell instead of EAC to enable MRSproxy:

Set-WebServicesVirtualDirectory "<ServerName>\EWS (Default Web Site)" -MRSProxyEnabled $true