Basic Networking in Hyper-V

From time to time in the forums, people seem to have varying understanding about the different networks available in Hyper-V. So I will try to explain some basic things here.

We have three types of Virtual Networks:

-         External

This is the network you have to configure if you want your VMs to have access to your LAN and
internet. During the creation of the External Virtual Network in Hyper-V, you have to select one of your installed NICs on your parent, to function as a Virtual Switch for your VMs.

Best practice is to not enable ‘Allow management operating system to share this network adapter’ if
possible. This is for isolation, and you need minimum 2 NICs to skip this feature. (Else you wont be able to connect to your host)

-         Private

This is a logical network, and is isolated from everything. It only allows communication between VMs on the same private network, and it is not bound to a physical NIC adapter.

(Some people (my colleague ;-)) think that this network doesn’t even allow your host to VMConnect to your VMs, that is not true. But you can’t access the VMs through your network, even from the host)

-         Internal

This network is similar to private virtual network, since it does not bound to a physical NIC adapter.

But the difference is that the internal network allows communication between the host and the VMs,

So you can communicate from your host to the VMs, between VMs, and from VMs to host.

So, since it`s so easy to create virtual networks, people seems to forget that networking on the virtual layer, have some similarities to a physical network.

That means that you have to ‘patch’ your VMs properly as well.

If you want to create two external virtual networks with different subnets and have communication between them, you would still need a default gateway configured on your VMs.

Even though the VMs is located on the same disk on the parent/shared storage, there would be no communication without a gateway and a routing between those subnets J