Designing Security for Communication Channels
Communication between computers may need to be secured on all levels, including a LAN. The most common reason why is to prevent "man-in-the-middle" attacks. Not "monkey-in-the-middle," but it's close. Basically, a fellow can intercept communications between two PCs and twist the data around. SMB-signing ensures that these attacks don't happen. You need to know how to configure it.
On a broader scale, IPSec is required. You'll need to know how IPSec works and how to configure it. The two primary components are policies and filters. You'll need to invest time in RRAS, VPNs, and IPSec to pass this portion of the exam.
Study Hint: Brush up on IPSec. It's sexy, exciting, and new to Windows 2000. You can expect to see plenty of it on this exam.