Network Unreachable Error

[abkap02]

Hi,

I'm trying to make use of iPXE to set up a diskless Ubuntu 16.04.2 Xenial Xerus boot via VirtualBox virtualization application. I have been able to successfully set up the server with Ubuntu Server 16.04.2 operating system using dnsmasq and nfs-kernel-server services running on it and when I make use of the preset PXE boot environment of the client virtual machine on VirtualBox everything works fine.

But when I'm trying to make ipxe.iso myself with an embedded script for amd64 machines as on http://ipxe.org/appnote/ubuntu_live which is:
#!ipxe

set server_ip 192.168.1.50
set nfs_path /tftpboot/ubuntu-14.04.1-desktop-amd64
kernel nfs://${server_ip}${nfs_path}/casper/vmlinuz.efi || read void
initrd nfs://${server_ip}${nfs_path}/casper/initrd.lz || read void
imgargs vmlinuz.efi initrd=initrd.lz root=/dev/nfs boot=casper netboot=nfs nfsroot=${server_ip}:${nfs_path} ip=dhcp splash quiet -- || read void
boot || read void

to be used to boot the client machine, it gives me a Network Unreachable error.

I'm using a bridged network configuration for my VirtualBox server with a static IP address and it does not require port forwarding in that mode.

Someone please lemme know what I must be missing or doing wrong here?

Thanks!