Unable to begin a Distributed transaction
Map a specific instance of SQL Server to a specific instance of MSDTC?

To map a SQL Server instance to an instance of MSDTC, open an administrative command prompt and use the msdtc.exe command. 

The following command is used to create a mapping between an instance of SQL Server and an instance of MSDTC.

msdtc -tmMappingSet -name &lt;MappingName&gt; -service &lt;SQLServerServiceName&gt; ^
-ClusterResourceName &lt;MSDTCResourceName&gt;


https://blogs.msdn.microsoft.com/alwaysonpro/2014/01/15/msdtc-recommendations-on-sql-failover-cluster/