MSDTC - how many ports are needed

Question

I have a considerably large application that uses MSDTC. How many ports should I open? Is there any way to determine it?

EDIT: I know what

Answer 1

When we've had to do this kind of debugging this article has been especially useful: How to troubleshoot MS DTC firewall issues. It includes an app called DTCPing which helps you to rapidly debug what the problem is.

As far as I remember the following ports were used:

TCP Port 1433 (Default port used by SQL Server)

UDP Port 1434 (Used by SQL Server)

TCP Port 3372 (Used by MSDTC.EXE)