Changing Delivery Controller addresses on VDA

This weekend the NetScaler gateway on one of our offices failed, rendering the office users unable to connect to their resources. I wanted to repoint all those users to the Delivery Controllers of a different office where the NetScaler was working, and ask users to temporarily connect via that. 

I had to two two things basically. 1) Change a registry key to repoint the VDA to the other Delivery Controllers. 2) Restart the VDA service (these machines were running 5.6(!!) so it’s called the Workstation Agent).