Facing issue on Azure AD connect

[sprazapati]

When I run application it is showing your domain is not routable. Use oth

[#2]

@sprazapati,

The following Microsoft post should assist you in preparing a non-routable domain for directory synchronization.

https://docs.microsoft.com/en-us/microsoft-365/enterprise/prepare-a-non-routable-domain-for-director...

[#3]

Thank You.

[#4 · Accepted solution]

You can still use a non-routable domain in the AAD connect, but the syned account to AzureAD will not have the preferred domain and will have @<tenantname>.onmicrosoft.com suffix.
You will have to go to MSOL PowerShell to change the UPN for the user.

connect-msolservice (enter the credentials of the Global admin or the relevant role based account)
set-msoluserprincipalname -userprincipalname user@<tenantname>.onmicrosoft.com -newuserprincipalname user@domain.com

[#5]

Thank You Sir