Troubleshooting AD servers for automatic query of Exchange Server

In a real-world build environment, a problem with a DC (multiple DC servers exist) is frequently encountered, and this DC is also a GC global catalog server. We know that Exchange automatically finds available GC servers randomly, regardless of whether the GC is available. An error occurs when a GC is found to be unavailable. Then, after 15 minutes, Exchange looks for another GC again. To avoid Exchange lookup of unavailable GC servers, we can debug the problematic GC server by setting up Exchange. The settings are as follows:

Get-exchangeserver | Set-exchangeserver-staticexcludeddomaincontrollers:ad.contoso.com

which

The parameter staticexcludeddomaincontrollers is followed by the FQDN of the DC that needs to be incorrectly drained.

Troubleshooting AD servers for automatic query of Exchange Server