Your network contains five servers that run Windows Server 2012 R2.
You install the Hyper-V server role on the servers. You create an external virtual network
switch on each server.
You plan to deploy five virtual machines to each Hyper-V server. Each virtual machine will
have a virtual network adapter that is connected to the external virtual network switch and
that has a VLAN identifier of 1.
Each virtual machine will run Windows Server 2012 R2. All of the virtual machines will run
the identical web application.
You plan to install the Network Load Balancing (NLB) feature on each virtual machine and
join each virtual machine to an NLB cluster. The cluster will be configured to use unicast
only.
You need to ensure that the NLB feature can distribute connections across all of the virtual
machines.
Solution: On each Hyper-V server, you create a new external virtual network switch. From
the properties of each virtual machine, you add a second virtual network adapter and
connect the new virtual network adapters to the new external virtual network switches.
Does this meet the goal?
A.
Yes
B.
No
Why would this not work?
Look at question 20. This is about being able to share MAC addresses between virtual machines in order to enable NLB.
http://blogs.technet.com/b/jhoward/archive/2009/05/21/new-in-hyper-v-windows-server-2008-r2- part-2-macspoofing.aspx
According to the official Ref Guide 70-414, Pages71-72 it would absolutely work.
Multicast mode is used when each NLB system has only 1 network adapter.
“Page71. In Unicast mode, which is the preferred mode when there are two or more network
adapters in a host”
“Page72. Unicast is appropriate when there’s more than one network adapter in the host.”
The answer is YES.
Yeah but you also need to enable MAC Address Spoofing.
There are several variations of this question, so here is a checklist of things to tick off when they ask for unicast mode:
1: Do you have more than one network adapter?
2: Is MAC Address Spoofing enabled?
Peter, please read this:
Since unicast NLB overwrite actual physical MAC address with virtual MAC on network cards that participating the unicast NLB and doing so actually \ technically stop node to node communication due to same MAC address on NICs.
In that case other servers \ devices can communicate with VIP of NLB and subsequently queries are redirected to NLB NICs
But In order to communicate between two nodes you must have another network card on those nodes so that node can communicate with each other
In case of multicast NLB, virtual MAC is appended to physical MAC of NICs that are part of NLB so that node can communicate with each other and same time can communicate with external network.
But above scenario is changed when virtualization is came to picture as weather you do unicast with one NIC, those are fake \ virtual network cards only and hyper-v \ VMware will manage to work with them somehow
Taken from Mahesh’s comment half way down:
http://www.experts-exchange.com/questions/28337860/Why-Unicast-NLB-server-needs-to-have-2-NIC-connected-to-different-IP-VLAN.html
I think B is correct, mac spoofing should also be enabled for Unicast NLB.
http://www.hyper-v.nu/archives/mvaneijk/2013/06/system-center-2012-sp1-service-provider-foundation-high-availability/#more-4676