SteelHead™ Deployment Guide - Protocols : RiOS Version Compatibility with Domains and Domain Relationships : User Domain Is the Same as Server Domain—Delegation Mode
  
User Domain Is the Same as Server Domain—Delegation Mode
Use the following tables when the user is in the same domain as the servers in question and you want to use Delegation mode.
 
Delegation Mode
Same Domain

Domain(Server)
Windows XP Clients
Windows Vista and Windows 2008 Clients
Windows 7 and Windows 2008-R2 Clients
Windows 2000
None
None
None
Windows 2003
RiOS v5.5
RiOS v5.5
RiOS v5.5
Windows 2008
RiOS v5.5
RiOS v5.5
RiOS v5.5
Windows 2008-R2
RiOS v6.1
RiOS v6.1
RiOS v6.1