# Troubleshooting MSDTC for RDS for SQL Server
<a name="Appendix.SQLServer.Options.MSDTC.Troubleshooting"></a>

In some cases, you might have trouble establishing a connection between MSDTC running on a client computer and the MSDTC service running on an RDS for SQL Server DB instance. If so, make sure of the following:
+ The inbound rules for the security group associated with the DB instance are configured correctly. For more information, see [Can't connect to Amazon RDS DB instance](CHAP_Troubleshooting.md#CHAP_Troubleshooting.Connecting).
+ Your client computer is configured correctly.
+ The MSDTC firewall rules on your client computer are enabled.

**To configure the client computer**

1. Open **Component Services**.

   Or, in **Server Manager**, choose **Tools**, and then choose **Component Services**.

1. Expand **Component Services**, expand **Computers**, expand **My Computer**, and then expand **Distributed Transaction Coordinator**.

1. Open the context (right-click) menu for **Local DTC** and choose **Properties**.

1. Choose the **Security** tab.

1. Choose all of the following:
   + **Network DTC Access**
   + **Allow Inbound**
   + **Allow Outbound**

1. Make sure that the correct authentication mode is chosen:
   + **Mutual Authentication Required** – The client machine is joined to the same domain as other nodes participating in distributed transaction, or there is a trust relationship configured between domains.
   + **No Authentication Required** – All other cases.

1. Choose **OK** to save your changes.

1. If prompted to restart the service, choose **Yes**.

**To enable MSDTC firewall rules**

1. Open Windows Firewall, then choose **Advanced settings**.

   Or, in **Server Manager**, choose **Tools**, and then choose **Windows Firewall with Advanced Security**.
**Note**  
Depending on your operating system, Windows Firewall might be called Windows Defender Firewall.

1. Choose **Inbound Rules** in the left pane.

1. Enable the following firewall rules, if they are not already enabled:
   + **Distributed Transaction Coordinator (RPC)**
   + **Distributed Transaction Coordinator (RPC)-EPMAP**
   + **Distributed Transaction Coordinator (TCP-In)**

1. Close Windows Firewall.