In a Symantec DLP installation, is there any communication over UDP (for example, between the Agent and the Endpoint Server)?
By default, most communication between different servers is TCP/IP based. No UDP is used. However, UDP is used by various components for internal communication, such as BoxMonitor, FileReader, Active Directory login, and others. In addition DLP can be configured to use UDP to communicate with syslog servers.
See Ports used by Symantec DLP for details.