sudo mkdir -p /etc/systemd/system/networking.service.d/
sudo bash -c 'echo -e "[Service]\nTimeoutStartSec=20sec" > /etc/systemd/system/networking.service.d/timeout.conf'
sudo systemctl daemon-reload

Source: networking – how to fix ” a start job is running for the raise network ” in ubuntu server 16.0 LTS – Ask Ubuntu

NAT EXPLANATION

Network Address Translation (NAT) is the simplest way of accessing an external network from a virtual machine. Usually, it does not require any configuration on the host network and guest system. For this reason, it is the default networking mode in VirtualBox.

A virtual machine with NAT enabled acts much like a real computer that connects to the Internet through a router. The “router”, in this case, is the VirtualBox networking engine, which maps traffic from and to the virtual machine transparently. In VirtualBox this router is placed between each virtual machine and the host. This separation maximizes security since by default virtual machines cannot talk to each other.

The disadvantage of NAT mode is that, much like a private network behind a router, the virtual machine is invisible and unreachable from the outside internet; you cannot run a server this way unless you set up port forwarding (described below).

BRIDGE EXPLANATION

With bridged networking, VirtualBox uses a device driver on your host system that filters data from your physical network adapter. This driver is therefore called a “net filter” driver. This allows VirtualBox to intercept data from the physical network and inject data into it, effectively creating a new network interface in software. When a guest is using such a new software interface, it looks to the host system as though the guest were physically connected to the interface using a network cable: the host can send data to the guest through that interface and receive data from it. This means that you can set up routing or bridging between the guest and the rest of your network.

Source: networking – Can’t get dhcp ip in my virtual machine on Virtual box – Super User

Source: How to Manually Set Your IP in Linux (including netplan) | Daniel Miessler

VBoxManage setproperty vrdeextpack “Oracle VM VirtualBox Extension Pack”

Source: virtualbox.org • View topic – rdesktop connection rejected – VRDE and VNC on same port

Changing Network Configuration

Below is an example of a static IP configuration on a system with only one Ethernet interface (eth0) and 10.0.0.41/24 for the IP address. Opening the /etc/network/interfaces file will produce:

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
iface eth0 inet static
    address 10.0.0.41
    netmask 255.255.255.0
    network 10.0.0.0
    broadcast 10.0.0.255
    gateway 10.0.0.1
    dns-nameservers 10.0.0.1 8.8.8.8
    dns-domain acme.com
    dns-search acme.com

Source: Configure Node Networking — SwiftStack Documentation