What's the difference between DTCPing and DTCTester?

Testing DTC settings is very common when installing BizTalk Server, so from the BTS documentation, so - from http://msdn.microsoft.com/en-us/library/aa561924.aspx

Use the DTCTester utility to verify transaction support between two computers if SQL Server is installed on one of the computers. The DTCTester utility uses ODBC to verify transaction support against a SQL Server database. For more information about DTCTester see How to Use DTCTester Tool.

Use DTCPing to verify transaction support between two computers if SQL Server is not installed on either computer. The DTCPing tool must be run on both the client and server computer and is a good alternative to the DTCTester utility when SQL Server is not installed on either computer. For more information about DTCPing, see How to troubleshoot MS DTC firewall issues.

This is not a direct answer to this question – but an important point to note.

1. The DTCPing windows application should be open in both the servers before you start test.

2. As per How To Use DTCTester Tool

Create an ODBC data source for your SQL Server through the ODBC utility in Control Panel.

References:

1. MSDTC problems
2. MSDTC THROUGH A FIREWALL TO AN SQL CLUSTER WITH RPC
3. Troubleshooting MSDTC issues with the DTCPing tool