Azure AD Connect - SQL Server Native Client 11

Question

We recently uninstalled Azure AD Connect from one our utility servers. After doing so, ODBC DSNs using SQL Server Native Client 11 were broken. In ODBC Manager these DSNs could not be configured and when highlighted the message at the bottom of the dialogue said the driver was missing and the only thing that could be done with the DSN was remove. We reinstalled Azure AD Connect and the DSNs were fully functional again. I searched far and wide and I did not find anything that shows a relationship between Azure AD Connect and SQL Server Native Client 11 and I certainly did not find anything that would warn me of this unintended consequence. Does anybody have any information on this?

Answer 1

It does say on https://learn.microsoft.com/en-us/azure/active-directory/hybrid/how-to-connect-install-prerequisites#azure-ad-connect-supporting-components that Azure AD Connect installs "Microsoft SQL Server 2019 Native Client" (which is a little bit of a misnomer, since I don't think there is any difference with what ship for SQL 2012 in this regard.)

If it uninstalls SQL Server Native Client unconditionally when installed, I would consider that to be a bug or design mistake. SQL Server Native Client could exist on a machine for many reasons.

Answer 2

Thanks for the quick response. After additional research I found that during the uninstall process the user can elect to "Also uninstall supporting components." One of the specifically mentioned supporting components is "Microsoft SQL Server 2012 Native Client." The root cause of the problem is Microsoft has assigned a multitude of names to the same thing. SQL Server Native Client 11 = Microsoft SQL Server 2012 Native Client = Microsoft SQL Server 2019 Native Client (apparently). While DBAs might know this tidbit of knowledge, it's going to be foreign to the data center team responsible for servers, VMs, and the maintenance of these so it's not surprising that even though our datacenter team knows there is a dependence on SQL Server Native Client 11, they would not equate this to SQL Server 2012 Native Client and therefore make the decision to "Also uninstall supporting components."