Two Exchange Servers and three Domain Controllers in the same AD site. All Domain Controllers are GCs.
Exchange is Exchange 2016 on Windows Server 2016. Domain Controllers are Windows Server 2019.
On Exchange01 everything works fine - using the Exchange Management Shell I can issue commands such as
Get-Mailbox successfully, and
Get-DomainController returns a list of all Domain Controllers.
Exchange02 gives "Could not find any available Global Catalog in forest".
On Exchange02 I can use regular PowerShell and issue commands such as
Get-ADUser which confirms AD connectivity is OK for this server.
On Exchange02 I can do
Get-ADForest | Select-Object -ExpandProperty GlobalCatalogs and it correctly lists all Global Catalogs.
The evidence indicates that this is localised to Exchange connectivity to AD on Exchange02.
This has only happened over the last day and there have been no changes to the environment.
So - how do I fix it?