title: Unable to ping Private IP of DMS Replication Instance from on-premises over Site-to-Site VPN & DMS source DB endpoint test connection fails
body: <p><strong>What am I trying to do?</strong></p>
  
  <p>I want to migrate and automatically replicate data from SQL Server in my on-premises Windows Server to DB in AWS Cloud. I am using AWS DMS (Database Migration Service) for this.</p>
  
  <p><strong>What have I done/tried already?</strong></p>
  
  <ul>
  <li>I have set up a site-to-site VPN (between on-premises network and AWS VPC)</li>
  <li>I am able to ping EC2 instance in VPN from Windows Server on-premises</li>
  <li>I am able to ping Windows Server on-premises from EC2 instance in VPN</li>
  <li>I have created a DMS Replication Instance. Its Private IP is within the allowed VPC CIDR of the VPN connection set already</li>
  <li>I am able to ping the Private IP of DMS Replication Instance from EC2 instance</li>
  <li>However, I am NOT able to ping the Private IP of DMS Replication Instance from Windows Server on-premises</li>
  <li>I have set-up a DB Server in my on-premises Windows Server. I added this DB as a DMS source endpoint. When I tried to test the connection, it failed with the following error message:</li>
  </ul>
  
  <p><a href="https://i.stack.imgur.com/88Aoh.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/88Aoh.png" alt="enter image description here"></a></p>
  
  <ul>
  <li>I have linked a Security Group to the DMS Replication Instance. This is the same Security Group I used in the VPN connection set up
  My DMS source DB endpoint configuration is as follows:</li>
  </ul>
  
  <p><a href="https://i.stack.imgur.com/N5tHM.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/N5tHM.png" alt="enter image description here"></a></p>
  
  <p><strong>What do I want to know?</strong></p>
  
  <p>Why am I not able to ping the private IP of DMS Replication Instance while I am able to ping an EC2 instance by setting up VPN
  Why the DMS endpoint test connection is failing?
  Could you help me in doing this DB migration please?</p>