Virtual Networks
Emulated adapter
A legacy adapter that makes calls directly to hypervisor. Slower, select Legacy network Adapter. Can boot the VM using PXE boot as loads drivers preboot. Does not require Guest Integration services.
Synthetic adapters:
A virtual adapter on a child partition that uses the VMbus to communicate to parent partition, better performance. Part of Guest Integration Services, not operational until the guest OS is loaded.
Recommended for VMs
At least two physical network adapters in a Hyper-V server, with one adapter servicing the parent partition and the other connected to the child partitions.
Creating Vswitch in PS
New-VMSwitch <switch name> -NetAdapterName <adapter name> [-SwitchType Internal|Private] New-VMSwitch "LAN Switch" -NetAdapterName "Ethernet"
Enable IPsec Task Offloading
Nic does IPsec crypto (encryption) on packets
Enable Virtual Machine Queue
Packets from VMs stored in separate queues on physical NIC and passed directly to VMs.
Enable Mac Address spoofing
Port on virtual switch can send and receive packets with any MAC address
Advanced network adapter features
Set a static Mac Address Enable Mac Address spoofing Enable DHCP guard Port Mirroring mode NIC Teaming
Private Vswitch
Switch exists only in Hyper V server and is only accessible to VMs on child partitions. Host OS can access physical adapter but not access virtual switch or virtual network. Can create multiple Private Vswitches
External Vswitch
Virtual switch is bound to network stack in host OS and connected to physical network adapter of host OS, access to external network Typical for production networks, access to internet, network services on physical networks. Can create only 1 external switch for each physical NIC.
Types of virtual switch
External Internal Private
Enable Single Root I/O Virtualisation SR-IOV
Enables creating an external virtual switch associated with an physical NIC that supports SR-IOV (only available when creating not modifying an existing Vswitch)
NIC limitations
Can create up to 12 network adapters on server 2012 HyperV Eight synthetic NICs and 4 emulated NICs
Allow Management Operating System to share this Network Adapter
Default is selected when external virtual switch created. Clear this box to exclude host OS from physical network but allow access to child VMs.
Enable DHCP guard
Detects and prevents rogue DHCP servers
Virtual Network
Each VM created has at least one virtual network adapter and is connected to a virtual switch. Can create unlimited multiple virtual switches in HyperV and multiple adapters on VMs
Hardware Acceleration settings
Enable Virtual Machine Queue Enable IPsec Task Offloading Single-Root I/O Virtualization
Port Mirroring mode
Forward all packets received on a port to another port for analysis (wireshark)
MAC addresses
HyperV creates a pool of 256 MAC addresses for assigning to VMs. View under Virtual Switch Manager, Global network settings, mac address range First 3 bytes are 00-15-5D (Microsoft OUI) 4th and 5th bytes are last 2 bytes of the IP address of the physical adapter.
NIC Teaming
Logically binds NICs and adds bandwidth NICs together.
Creating Virtual switches
The hyperV role enables Create virtual switches wizard. Can create a virtual switch for each of the physical network adapters in the host so VMs can send to actual switches that physical adapters connected to. Network adapter in host OS is connected to virtual switch and this is connected to physical switch. Provides external connections to network, can obtain IP info from LAN DHCP or be the LAN DHCP.
Enable VLAN Identification for Management Operating system
Tick this box and enter VLAN ID to associate virtual switch with a particular VLAN on physical network.
Internal Vswitch
VSwitch is a separate instance of networking stack, independent of physical adapter of host OS. All VMs, host (parent) and child can access virtual switch. Only Host OS can access the physical adapter on external network. Child partitions cannot access external network. Can create multiple Internal Vswitches
