Hi Nathan,
Basics: make sure you have a Remote Agent license installed. This will be a site license and the agent can be installed on as any servers at your site.
Next: check the versions of this file and make sure they are the same
-- Backup Exec Server = C:\Program Files\Symantec\Backup Exec\beremote.exe
-- Remote Server = C:\Program Files\Symantec\Backup Exec\RAWS\beremote.exe
If the agent is not installed or if the version does not match the Backup Exec server, install (reinstall) the agent.
If the NSA-DC1 box is a Netapp or NAS box or SNAP server, you may not be able to install the remote agent on it. If this is the case, then you will need to create a "User Defined Share" and make your selections from there.
How to create a user-defined selection in Backup Exec for Windows Servers