Cut over | Staged | Hybrid | IMAP | |
---|---|---|---|---|
Exchange Versions | 2003 and later | 2003 / 2007 | 2010 / 2013 | 2000 Onward |
Pros | Simple | Greater than 2000 users | More time (no down time) | Migrate legacy mailboxes |
Cons | Max 2000 Users | Coexistence | Requires Hybrid Exchange Wizard | Only Inbox Migrated |
Cons | Max 2000 Users | Coexistence | Requires Hybrid Exchange Wizard |
Cut over Migration
A cut over migration is a “all at once” method of migrating.
Prerequisites
Outlook anywhere (HTTP over RPC) AKA Auto discover
SSL Certificates
Custom domain added to Office 365 tenant account
Preparing the Cut over Migration
If Outlook anywhere / auto discover is already configured, skip to step 7.
1. Create a Custom certificate request
Template: (No Template) Legacy KeyPKCS #10Certificate Name: Outlook AnywhereCommon name: CN=domain.comEnter an Alternative DNS: autodiscover.domain.com and mail.domain.comExtended Key Language: Server AuthenticationKey Type: ExchangeKey Size: 2048Make Key ExportableSave CSR as Base64.
2. Submit the CSR to a public CA. Once it’s received, import the certificate
3. Export the certificate
Export Private key: yes
PKCS #12
Save the certificate to the exchange server
4. Check firewall for required ports
HTTPS: 443
5. Create DNS Records (CNAMEs)
mail.domain.comautodiscover.domain.com
6. Import the Certificate into Exchange
Open IISLocate the OWA SiteAssign the certificate to the https bindings.
7. Test exchange connectivity
Executing the Migration
1. Ensure the on-premises account has correct permissions
2. Add the domain to Office 365
Only step 1 is required for this process there is no need to add licences yet as there are no accounts in Office 365 to assign them to.
3. On the on-Premises exchange, go to Migration
Select cut over migrationEnter credentials of the administratorEnter the exchange server: exchange.ADDomain.localEnter the RPC Proxy: mail.domain.comName the Migration Batch: Batch 1
The batch will then run.
4. Change the MX Records to point to Office 365
5. Disable Synchronization and delete batch on the local exchange
6. Decommission Server
Guide to continue…