Dude wrote:Perfecto Mundo.
The NAT interface uses the host network as a proxy to make connections on behalf of the virtual machine. The VirtualBox built-in DHCP server, which you must use with this interface, also forwards DNS queries.
The /etc/hosts file has normally precedence over DNS resolving. You can check /etc/nsswitch.conf. If a host record is found in /etc/hosts, DNS will not be queried. You could for instance add the following entry to your /etc/hosts file of your Linux guest system so that the query goes nowhere, or use the TCP/IP address it should use.
0.0.0.0 datacenter datacenter.example.com