This is the value used in the RFC 5424 header as the "HOSTNAME", and in most cases,
this should be the fully qualified domain name of the machine sending audit messages.
In some cases however (e.g. for testing when passing through NAT proxies) it may be necessary
to use the externally visible address of the proxy.
Requirements
Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2