Creating a Network Topology using VMs in VirtualBox

In my earlier posts, I covered How to - Create a Ubuntu VM in Virtualbox, topics related that and Networking for VirtualBox VMs.

In this post, I will provide steps to create the following simple network topology using VirtualBox VMs:

                     H1  <----->  R1  <----->  R2  <----->  H2

As we need only interconnectivity among the VMs, we can use "Internal Networking" mode as detailed in Networking for VirtualBox VMs. Also, I am going to leave the default NAT mode enabled VM adapters as-is. Instead, I will use the remaining VM adapters to create the above topology.

• Right click VM H1, select "Settings", select "Network" tab, select "Adapter2", check "Enable Network Adapter", choose "Internal Network" in "Attached to". Then provide a name in "Name" field. This name & the name we provide in VM R1's Adapter should match. The VM adapters with matching names will be connected.

             

• Right click VM R1, select "Settings", select "Network" tab, select "Adapter2", check "Enable Network Adapter", choose "Internal Network" in "Attached to". Then provide a name in "Name" field. This name & the name we provide in VM H1's Adapter should match. The VM adapters with matching names will be connected.

             

• Now the link "H1  <----->  R1" is established.

• Similarly, I established the other two links: "R1  <----->  R2" & "R2  <----->  H2"

Now, I booted my VMs, configured IP addresses & ran ping tests to check whether work fine. Here, I am providing screenshots of H1 & R1 VM bash terminals:

              

             

References:

http://www.brianlinkletter.com/how-to-use-virtualbox-to-emulate-a-network/

Networking for VirtualBox VMs

In my earlier posts, I covered How to - Create a Ubuntu VM in Virtualbox and topics related that. In this post, I will cover basics of networking techniques for VirtualBox VMs.

Networking is necessary to connect the VM to/from internet or establish connectivity among the VMs. The following are different ways of networking (copy-pasted from https://www.virtualbox.org/manual/ch06.html#networkingmodes):

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VirtualBox provides up to eight virtual PCI Ethernet cards for each virtual machine. We can configure only four of these form GUI. CLI allows to configure all the eight interfaces.

Each of the eight networking adapters can be separately configured to operate in one of the following modes:

Not attached

In this mode, VirtualBox reports to the guest that a network card is present, but that there is no connection -- as if no Ethernet cable was plugged into the card. This way it is possible to "pull" the virtual Ethernet cable and disrupt the connection, which can be useful to inform a guest operating system that no network connection is available and enforce a reconfiguration.

Network Address Translation (NAT)

If all you want is to browse the Web, download files and view e-mail inside the guest, then this default mode should be sufficient for you, and you can safely skip the rest of this section. Please note that there are certain limitations when using Windows file sharing (see Section 6.3.3, “NAT limitations” for details).

NAT Network

The NAT network is a new NAT flavour introduced in VirtualBox 4.3. See 6.4 for details.

Bridged networking

This is for more advanced networking needs such as network simulations and running servers in a guest. When enabled, VirtualBox connects to one of your installed network cards and exchanges network packets directly, circumventing your host operating system's network stack.

Internal networking

This can be used to create a different kind of software-based network which is visible to selected virtual machines, but not to applications running on the host or to the outside world.

Host-only networking

This can be used to create a network containing the host and a set of virtual machines, without the need for the host's physical network interface. Instead, a virtual network interface (similar to a loopback interface) is created on the host, providing connectivity among virtual machines and the host.

Generic networking

Rarely used modes share the same generic network interface, by allowing the user to select a driver which can be included with VirtualBox or be distributed in an extension pack.
At the moment there are potentially two available sub-modes:

UDP Tunnel

This can be used to interconnect virtual machines running on different hosts directly, easily and transparently, over existing network infrastructure.

VDE (Virtual Distributed Ethernet) networking

This option can be used to connect to a Virtual Distributed Ethernet switch on a Linux or a FreeBSD host. At the moment this needs compiling VirtualBox from sources, as the Oracle packages do not include it.

The following table provides a quick overview of the most important networking modes:

Table 6.1. Overview

	VM ↔ Host	VM1 ↔ VM2	VM → Internet	VM ← Internet
Host-only	+	+	–	–
Internal	–	+	–	–
Bridged	+	+	+	+
NAT	–	–	+	Port forwarding
NAT Network	–	+	+	Port forwarding

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After creating the VM, the default mode is NAT. So, I was able to connect to internet without any additional configuration. Select a VM & Right click, select "Settings", "Network" tab to see the VM's default networking config:

             

References:

https://www.virtualbox.org/manual/ch03.html#settings-network

https://www.virtualbox.org/manual/ch06.html#networkingmodes

How to manage VM groups in VirtualBox - Create/Rename/Delete Groups, Add/Delete VMs

In this post, I will provide steps to create and manage VM groups in VirtualBox. If I call for a VM creation in this post, please refer to my earlier blog: How to - Create a Ubuntu VM in Virtualbox

Why do we need a VM group?

I recently started creating a few network topologies & so grouping VMS belonging to one topology into one group made it easy for me to manage my topologies and VMs. Simply, grouping helps you organize your VMs better.

How to create a VM group?

• Select the VMs to be grouped, right click & select "Group":

             

• The above steps names the group as "New Group":

             

How to add a new VM to an existing VM group?

• Drag and drop the VM into the new group.

How to delete a VM from an existing VM group?

• Drag and drop the VM from the group to an empty place in the VM list menu

How to rename a VM group?

• Right click on the group name & select "Rename Group":

             

How to ungroup a VM group?

• Right click on the group name & select "Ungroup":

             

References:

http://www.sysprobs.com/how-to-create-manage-vm-groups-in-virtualbox-virtual-machines

http://www.brianlinkletter.com/how-to-use-virtualbox-to-emulate-a-network/

"VirtualBox Guest Additions" Installation error - Unable to insert the virtual optical disk

To copy paste from Virtualbox guest to host & vice versa, I typically follow the steps listed in my earlier blog post - How to - copy/paste from VirtualBox guest to host & viceversa. Though it worked for me many times, I got the following error pop up recently when I clicked on the "Devices" in top bar menu and clicked on "Insert Guest Additions CD image...":

             

In this post, I will provide steps to install the "VirtualBox Guest Additions" in an alternate way.

• Shut down the VM

• I right clicked on my VM in Virtualbox Manager, clicked on the "Settings" displayed menu, selected "Storage" tab, right clicked on "VBoxGuestAdditions" & clicked on "Remove attachment":

             

• Clicked the "+" icon next to "Controller: IDE" to add a new optical drive. Choose "Leave Empty --> Okay":

             

             

• After this, restart the VM & follow the same steps as I mentioned in my earlier blog post - How to - copy/paste from VirtualBox guest to host & viceversa to install "VirtualBox Guest Additions".

References:

https://askubuntu.com/questions/573596/unable-to-install-guest-additions-cd-image-on-virtual-box