If you like your Hyper-V story to run smoothly your server needs two network cards – my HP DL380 has two gigabit cards – one is used for Hyper-V server to have internet connectivity (updates, remote management …) second one is given to Virtual network manager to be used by virtual machines.
If you did not select any network adapters to be used by Hyper-V during Hyper-V installation you can see your physical two adapters in Network connections.
After you run Virtual network manager and you create new network for example “External network” that is connected to your second physical card your physical card lose connectivity and all protocols and services are unchecked except Microsoft Virtual Network Switch Protocol (and HP Network configuration utility – but this is specific to my case becouse I use HP server). When you finish the wizard you can see that in your Network connections there is another adapter called “External network” – it is now used for your Virtual machines.
HINT! Do not do that remotely if you are not completely shure which adapter is which… If you make a mistake you will need physical access to the machine to change network parameters. 🙂
Example:
Hyper-V virtual network manager example [docx]
Hyper-V virtual network manager example [pdf]
Luka Manojlovic 
I realize this post is 1.5 years old, but maybe you can help me. By using two nics in the way you show, can I somehow set the virtual network on the 2nd nic to live on a different subnet, yet still get to the internet? Here’s a diagram of what I’m trying to accomplish: http://thatcomputergeek.com/images/arrr2.jpg
Hope you can help!
LikeLike
Well if you have 2 nic you need to configure 2 external networks using network manager.
And yes you can do that but you will need some kind of routing between two networks. You can also do that but you will need to configure routing in Windows server (one of virtual machines that will have two network cards) – not on Hyper-V host!
LikeLike
Hi!
Tudi pri nas imamo problem z ve?imi NIC kartami.
Slika je slede?a.
Brez virtualizacije imamo kar nekaj stre?nikov z dvema NIC kartama. Ena veja slu?i kot komunikacija med DB in APP stre?niki (to je tudi v svojem VLANu) druga veja (NIC karta) pa slu?i za dostop uporabnikov do aplikacij.
Vpra?anje:
Kaj je dobra praksa za postavitev dveh ali treh tovrstnih stre?nikov v virtualno okolje.
LP
Jan
LikeLike