What is NX and DX?

I remember coming across this term when I was studying for my #VCAP-DCD.  I was not for sure what is means.

So here is the break down:

NX/XD is a BIOS setting.

NX is the AMD “No Execute”

XD is the Intel “Execute Disabled”

They mark memory pages as data-only to prevent malicious software exploits and buffer overflow attacks.

After ESXESXi 3.X or later NX and XD are exposed to the to guest operating system by default.

Now you know.