By default ISA/TMG does not allow outbound SSH traffic. And in the log it shows something like this:



To make it work, you have to extend the ISA/TMG ports by adding SSH/22 by using isa_tpr.js. Here is my example:

c:\Utils>cscript isa_tpr.js /add SSH 22
Microsoft (R) Windows Script Host Version 5.8
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The Web Proxy service should be restarted to pick up the change.

This is the definition for SSH:

SSH (single port): 22