Cloud virtual machines, including network appliances like VNS3, can have additional network interfaces added to them dynamically. If you have ever worked on actual computer hardware you will appreciate how much EASIER this is! No screwdriver required. 

However, in the cloud, even though Amazon, Azure, Google, etc.. have made adding interfaces really easy, there is usually some non-trivial work to do for getting those interfaces configured in your virtual appliance. Search via a web browser for “Add additional network interfaces, AWS, ?” (where “?” is replaced by your favorite vendor of datacenter network products (Cisco, Juniper, F5, etc..).

What you will find are instructions which include steps for remote shell into the device (get security keys, port 22 access), bring up a command line terminal and use a variety of operating system or vendor specific configuration commands. 

NOT WITH VNS3. Let’s take a look. 

Here is a link to a 3m30s video which shows the whole process (skip to the last 20 seconds) if you don’t want to read any further.

Here is how simple it is:

1. Go to VNS3 Interfaces page to verify interface is not already attached.

2. In the Amazon (or Azure or Google) portal, attach a new interface to the VNS3 Controller.

3. Go back to the VNS3 Interfaces page, and within seconds you will see the new interface attached, and configured with its private ip address and its public ip (if there is one).

That’s it.  In our example “eth1” is now attached and configured!

No remote shell. No command line. No operating system or product configuration commands.

(Note: By default we bring new interfaces into the system in a disabled state.)

If you want a little more context please take a look at the video link at the top of this post.