Windows Server Domain and Forest Functional Levels

ref.: http://blogs.techrepublic.com.com/datacenter/?p=308

	2000 native	2003 native	2008 native
DCs allowed	W2K, W2K3, W2K8	W2K3, W2K8	W2K8 only
Domain features	Universal groups, Group nesting, Group conversions, Security identifier (SID) history	Ability to rename domain controllers via netdom.exe, Logon time stamp dates, Redirect Users and Computers, Authorization Manager policies in AD, Constrained delegation, Selective authentication	Distributed File System replication support for SYSVOL, Advanced encryption, Last Interactive Logon information, Fine-grained password policies
Forest features	All default AD features	Forest trust, domain rename, linked-value replication, Read-only domain controller deployment, instances of the dynamic auxiliary class named dynamicObject in a domain directory partition, convert inetOrgPerson object instance into a User object instance, create instances of new group types to support role-based authorization, deactivation and redefinition of attributes and classes in the schema	No new additional forest-level features

ICMP Security Failures Messages

Error Procedures

   As is usual with ICMP messages, upon receipt of one of these error
   messages that is uninterpretable or otherwise contains an error, no
   ICMP error message is sent in response.  Instead, the message is
   silently discarded.  However, for diagnosis of problems, a node
   SHOULD provide the capability of logging the error, including the
   contents of the silently discarded datagram, and SHOULD record the
   event in a statistics counter.

   On receipt, special care MUST be taken that the ICMP message actually
   includes information that matches a previously sent IP datagram.
   Otherwise, this might provide an opportunity for a denial of service
   attack.

Install X server via YUM on Redhat/CentOS

First you can see all the yum groups available with the command:

yum grouplist

You can install X and Gnome or KDE like this:

yum groupinstall "X Window System" "GNOME Desktop Environment"

or

yum groupinstall "X Window System" "KDE (K Desktop Environment)"

You may also want to add some other groups from the list like "Graphical Internet" or "Office/Productivity"
ref: http://wikinux.wetpaint.com/page/Install+X+server+via+YUM+on+Redhat%2FCentOS