Configuring the Boot Server (Next Server) of a NAT Network Interface
For network booting in NAT mode, by default uses
a built-in TFTP server at the IP address 10.0.2.4. This default
behavior should work fine for typical remote-booting scenarios.
However, it is possible to change the boot server IP and the
location of the boot image with the following commands:
$ VBoxManage modifyvm VM-name \
--nattftpserver1 10.0.2.2
$ VBoxManage modifyvm VM-name \
--nattftpfile1 /srv/tftp/boot/MyPXEBoot.pxe