References

• https://www.virtualbox.org/manual/ch06.html
• https://www.nakivo.com/blog/virtualbox-network-setting-guide/

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ViratualBox Network Modes

• Not attached (No connection)
• NAT
• NAT Network
• Bridged Adapter
• Internal networking
• Host-only
• Generic (shared with the host)

NAT

• Sufficient in most cases
• Internet-enabled: from Internal network to Internet access is possible
• Guests on internel network CANNOT talk each other
• (from www.nakivo.com)
• Enabling NAT for a VM with VBoxManage: VBoxManage modifyvm VM_name --nic1 nat
  • VM_name: name of a virtual machine
  • nic1: number of virtual machine adapter

NAT Network

• Similar to NAT, but guest CAN talk each other
• basically,, CANNOT access guest machines either from the host or from external network
  • However, “Port forwarding” enables the host or the machines of the host network to access guests
• A built-in VBox NAT router uses
• Network address and name can be changed: (Global preference) File > Preferences > Network > Edit the settings(icon): Default address 10.0.2.0/24(GW 10.0.2.1, DHCP 10.0.2.3) can be changed to 192.168.xx.0/24(GW x.x.x.1, DHCP x.x.x.3)
• (from www.nakivo.com)
• Adding a new NAT Network with VBoxManage: VBoxManage natnetwork add --netname mynatnet1 --network "192.168.15.0/24" --enable
• Configuring a VM to use NAT Network with VBoxManage: VBoxManage modifyvm VM_name --nic1 natnetwork
  • nic1: the first virtual network adapter(network interface controller)

Bridged Adapter

• The host and guest share the physical NIC (thanks to net filter)
• Guests can access the Internet as the host does
• “Promiscuous mode” can be enabled with this mode
• (from www.nakivo.com)

Internal

• Guests can talk each other, but CANNOT communicate with the host nor access to the external network
• models real networks
• (from www.nakivo.com)

Host-only

• Geusts and the host can talk each other
• A Host-only network adapter can be set by File > Host Network Manager > (Adapter tab)
  • Default network address can be changed
  • DHCP can be set on/off
  • No Gateway presented (since outer world do not access into the host-only network)
• (from www.nakivo.com)

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Create a subnet using the host-only networking mode

Review a virtual switch

• File > Host Network Manager
• on “Host Network Manager” window, click the “Properties”(of “vboxnet0”) button
  • Default IP: 192.168.56.1/24
  • Default DHCP: Enabled, 192.168.56.100/24 (192.168.56.101~192.168.56.254)

Create another virtual switch for host-only networking

• [Trial1] We might want to create vboxnet1 and give the following properties:
  • Default IP: 10.20.30.1/24
  • Default DHCP: Disabled
• That cannot be done simply (https://forums.virtualbox.org/viewtopic.php?t=104357)
• [Trial2] create /etc/vbox/networks.conf that has the following line:

  * 10.20.30.0/24
  

  • In that file, “#” is used for comments
  • Examples in the above thread

    * 10.0.0.0/8 192.168.0.0/16
    * 2001::/64
    

  • * 0.0.0.0/0 ::/0 allows any addresses (range control is disabled)
  • if /etc/vbox/networks.conf file exists with no ranges are specified, then no addresses will be assigned to host-only adapters
  • now, vboxnet1 can be set as follows: