network using the Provider Address network to ensure the traffic arrives on the Hyper-V host where the destination machine is residing. Outbound traffic has the NVGRE header information removed from packets as they leave the gateway server, and the recipients of this traffic are unaware that the source is actually contained within an HNV network. Implementing Network Isolation in Hyper-V In this chapter we will cover the following recipes: Understanding VLANs in Hyper-V and VMM, including the PowerShell cmdlets Understanding Private VLANs in Hyper-V and VMM, including the PowerShell cmdlets Introduction In addition to Hyper-V Network Virtualization (HNV), it is possible to achieve network isolation using traditional VLANs and Private VLANs. VLAN tags are added by the Hyper-V Extensible Switch and not by the guest operating system inside the VM. VMs are not aware that their traffic is being tagged. Private VLANs offer a different type of isolation, which can help break a VLAN into multiple sub-VLANs. In the case of Private VLANs, VMs are unaware of their participation in a Private VLAN. Understanding VLANs in Hyper-V and VMM, including the PowerShell cmdlets VLANs in Hyper-V allow for the isolation of traffic. It is possible to set a network adapter to trunk VLANs into a VM; an example use case for this could be a network load balancer that is responsible for multiple VLANs. Implementing Network Isolation in Hyper-V Getting ready In this recipe you will be creating additional VLANs in VMM and will require a new VLAN ID and subnet. How to do it... The following diagram shows you the high-level steps involved in this recipe: Overview of Recipe: Prerequisites (not covered by this recipe): Determine which VLAN IDs to create in VMM Actions: Creation of a Logical Network for VLAN Isolation Creating of a Logical Network Site with 2 VLANs Creating 2 VM Networks for VLANs Creating a VM in one of the new VLANs This table shows you the VLANs and the settings that will be applied: Setting Name Value Logical Network Name VLAN 