The logon client will discover the logon agent by looking up a hostname called dswagent2 or dswsslagent2 in your DNS server.
Because you created a virtual domain, you must add the DNS entries in a corresponding lookup zone.
To add a new forward lookup zone open DNS Manager expand the server name, right-click on Forward Lookup Zones and select New Zone
Keep the default settings in the New Zone Wizard
Enter the name of the virtual domain you created on DualShield
Add new host A records for your dswagent2 and dswsslagent2:
Make sure you can ping the agent from the end client workstation.