HowTo: Migration from Exchange 2016 to Exchange 2019 (Part 2)

Part 1 of the article series "Migration from Exchange 2016 to Exchange 2019" only described the test environment and the installation of Exchange 2019. Now the more interesting steps follow. This part now deals with the configuration of Exchange 2019 for co-existence with Exchange 2016.

The aim of this article is to have a functional Exchange 2019 server, which will later replace the Exchange 2016 server. The certificate and also the URLs (e.g. OWA) should be retained. Users should therefore not have to remember a new URL for OWA. Existing applications that interact with Exchange should also not be affected by the migration (assuming compatibility).

Exchange 2019 configuration

The first configuration I make on a new Exchange Server is to rename and move the database to its destination. This is done quickly using the Exchange Management Shell:

Get-MailboxDatabase -Server Exchange2019 | Set-MailboxDatabase -Name DB2019
Move-DatabasePath DB2019 -EdbFilePath d:\DB2019\DB2019.edb -LogFolderPath d:\DB2019

So that Exchange 2019 can also deliver mails to the Internet, the new server must be entered as the source server for the send connector:

Only the Exchange 2019 server needs to be added here. If there are other send connectors, the new server must also be entered here:

Next up are the URLs for the various virtual directories.

To avoid having to configure each of the Exchange URLs manually, the following small script can be used. Only the first two lines need to be adapted and the respective host names of Exchange 2016 and Exchange 2019 entered. The script then reads the URLs from the Exchange 2016 configuration and configures the same settings for Exchange 2019:

$Exchange2019Server = "Exchange2019"
$Exchange2016Server = "Exchange16"
#Get URLs from Exchange 2016 Server
$autodiscoverhostname = (Get-ClientAccessService $Exchange2016Server).AutoDiscoverServiceInternalUri
$owainturl = (Get-OwaVirtualDirectory -Server $Exchange2016Server).internalurl
$owaexturl = (Get-OwaVirtualDirectory -Server $Exchange2016Server).externalurl
$ecpinturl = (Get-EcpVirtualDirectory -server $Exchange2016Server).internalurl
$ecpexturl = (Get-EcpVirtualDirectory -server $Exchange2016Server).externalurl
$ewsinturl = (Get-WebServicesVirtualDirectory -Server $Exchange2016Server).internalurl
$ewsexturl = (Get-WebServicesVirtualDirectory -Server $Exchange2016Server).externalurl
$easinturl = (Get-ActiveSyncVirtualDirectory -Server $Exchange2016Server).internalurl
$easexturl = (Get-ActiveSyncVirtualDirectory -Server $Exchange2016Server).externalurl
$oabinturl = (Get-OabVirtualDirectory -server $Exchange2016Server).internalurl
$oabexturl = (Get-OabVirtualDirectory -server $Exchange2016Server).externalurl
$mapiinturl = (Get-MapiVirtualDirectory -server $Exchange2016Server).internalurl
$mapiexturl = (Get-MapiVirtualDirectory -server $Exchange2016Server).externalurl
$OutlAnyInt = (Get-OutlookAnywhere -Server $Exchange2016Server).internalhostname
$OutlAnyExt = (Get-OutlookAnywhere -Server $Exchange2016Server).externalhostname
#Configure Exchange 2019 Server
Get-OwaVirtualDirectory -Server $Exchange2019Server | Set-OwaVirtualDirectory -internalurl $owainturl -externalurl $owaexturl -Confirm:$false
Get-EcpVirtualDirectory -server $Exchange2019Server | Set-EcpVirtualDirectory -internalurl $ecpinturl -externalurl $ecpexturl -Confirm:$false
Get-WebServicesVirtualDirectory -server $Exchange2019Server | Set-WebServicesVirtualDirectory -internalurl $ewsinturl -externalurl $ewsexturl -Confirm:$false
Get-ActiveSyncVirtualDirectory -Server $Exchange2019Server | Set-ActiveSyncVirtualDirectory -internalurl $easinturl -externalurl $easexturl -Confirm:$false
Get-OabVirtualDirectory -Server $Exchange2019Server | Set-OabVirtualDirectory -internalurl $oabinturl -externalurl $oabexturl -Confirm:$false
Get-MapiVirtualDirectory -Server $Exchange2019Server | Set-MapiVirtualDirectory -externalurl $mapiexturl -internalurl $mapiinturl -Confirm:$false
Get-OutlookAnywhere -Server $Exchange2019Server | Set-OutlookAnywhere -externalhostname $OutlAnyExt -internalhostname $OutlAnyInt -ExternalClientsRequireSsl:$true -InternalClientsRequireSsl:$true -ExternalClientAuthenticationMethod 'Negotiate' -Confirm:$false
Get-ClientAccessService $Exchange2019Server | Set-ClientAccessService -AutoDiscoverServiceInternalUri $autodiscoverhostname -Confirm:$false
#Display setttings
Get-OwaVirtualDirectory | fl server,externalurl,internalurl
Get-EcpVirtualDirectory | fl server,externalurl,internalurl
Get-WebServicesVirtualDirectory | fl server,externalurl,internalurl
Get-ActiveSyncVirtualDirectory | fl server,externalurl,internalurl
Get-OabVirtualDirectory | fl server,externalurl,internalurl
Get-MapiVirtualDirectory | fl server,externalurl,internalurl
Get-OutlookAnywhere | fl servername,ExternalHostname,InternalHostname
Get-ClientAccessService | fl name,AutoDiscoverServiceInternalUri

The configured URLs are listed at the end and should be checked once. Both servers must have the same URLs:

That is actually all there is to it.

To be on the safe side, however, you should go through the complete Exchange 2016 configuration and configure Exchange 2019 accordingly. For example, settings for the receive and send connectors (relay settings, throttling, message size)

The database settings are also important; the limits should also be adjusted here. It would not be nice if, for example, 10 GB was set as the maximum for mailboxes on the Exchange 2016 server, but only 2 GB on Exchange 2019. When data is later transferred from Exchange 2016 to Exchange 2016, a 5 GB mailbox would be over the limit and Exchange would prohibit sending and receiving.

Take over certificate

Once Exchange 2019 has been configured, the certificate can be transferred. To do this, the certificate must first be exported from the Exchange 2016 server:

The certificate is now saved directly on the Exchange 2019 server. At this point, you can of course also specify any other share that can be reached from both servers. Password and path are required again for the import:

The previously exported certificate can now be imported to the Exchange 2019 server:

The path and password of the exported certificate must be entered here:

In the last step of the dialog, the Exchange 2019 server on which the certificate is to be installed is specified:

After the certificate has been installed, the Exchange services must be bound to the certificate:

Exchange 2019 is now able to work as a proxy for Exchange 2016. It is now a good idea to carry out a few tests by editing the hosts file of a client. In this example, I would now adjust the hosts file on a client and let outlook.frankysweblab.de point to the IP of the Exchange 2019 server. If the first tests were successful, the DNS and firewall can be changed.

Change DNS and firewall

The IP address for the entries "outlook.frankysweblab.de" and autodiscover.frankysweblab.de" must now be changed on the internal DNS server. Currently, both entries point to the IP of the Exchange 2016 server:

The IP of the two Host-A entries is now changed to the IP of the Exchange 2019 server. In this case 192.168.200.18:

To ensure that external clients are also referred to Exchange 2019, the NAT entry still needs to be adjusted; it currently points to Exchange 2016:

The port forward only needs to be changed to Exchange 2019 at this point:

Following these changes, Exchange 2019 is now a CAS proxy for Exchange 2016. The users' mailboxes are currently still hosted on Exchange 2016. The migration of the data is part of the next article, which will follow shortly.

At this point, it is recommended to go through the DNS entries: Other DNS entries, such as CNAMES and SRV records (Autodiscover) should also point to Exchange 2019. In many environments, CNAMES have been configured to the hostname of the (old) Exchange server (for example, for SMTP traffic from other devices/applications). Devices such as printers / scanners should also be checked once, experience has shown that the IP is often used here instead of an FQDN.

In dieser Konstellation kann jetzt Exchange 2019 erst einmal parallel zu Exchange 2016 laufen. Wenn sich keine Probleme ergeben, kann mit der Datenmigration weiter gemacht werden. Sollten doch Probleme auftreten, können mit wenig Aufwand die DNS- und NAT Einstellungen rückgängig gemacht werden.

Data migration is part of the next article.