How to Configure Network Settings on a Hyper-V Host in VMM

 

Updated: May 13, 2016

Applies To: System Center 2012 SP1 - Virtual Machine Manager, System Center 2012 R2 Virtual Machine Manager, System Center 2012 - Virtual Machine Manager

After you use Virtual Machine Manager (VMM) to configure logical networks for your environment, for example, a “Backend,” “Frontend,” and “Backup” network, you must take at least one more step before anyone can use those logical networks for connecting to or from virtual machines. That step is to assign the logical networks to physical network adapters on one or more hosts. This topic describes one way to take that step in Virtual Machine Manager (VMM), but there’s another topic that describes a different way, as outlined in the following table:

If you have... And you want to... Follow steps in...
System Center 2012 Assign logical networks to a physical network adapter This topic
System Center 2012 Service Pack 1 (SP1) or
System Center 2012 R2
Assign logical networks manually to each physical network adapter This topic
System Center 2012 SP1 or
System Center 2012 R2
Assign the same logical networks and other network settings consistently to multiple physical network adapters across multiple hosts How to Configure Network Settings on a Host by Applying a Logical Switch in VMM

Do the tasks in this topic in this order:

  1. Assign logical networks to a physical network adapter on a host

  2. Configure settings for external, internal, and private virtual networks

Assign logical networks to a physical network adapter on a host

This procedure describes how to open host properties and configure a network adapter with the Logical network connectivity setting.

To assign logical networks to a physical network adapter on a host

  1. Make sure that you have already created the logical networks that you want to assign to one or more physical network adapters. Also make sure that the network sites within your logical networks are configured to use the host group of the host you want to assign them to. Both of these steps are described in How to Create a Logical Network in VMM.

  2. In the VMM console, open the Fabric workspace.

  3. In the Fabric pane, expand Servers, expand All Hosts, and then locate and click the host group that contains the host.

  4. In the Hosts pane, click the host that you want to configure.

  5. On the Host tab, in the Properties group, click Properties.

  6. In the Host Name Properties dialog box, click the Hardware tab.

  7. Under Network Adapters, click the physical network adapter that you want to configure. If you want to use this network adapter for virtual machines, ensure that Available for placement is checked. If you want to use this network adapter for communication between the host and the VMM management server, ensure that Used by management is checked.

    Important

    You must make sure that you have at least one network adapter available for communication between the host and the VMM management server. Make sure that Used by management is checked for this network adapter.

  8. View or click Logical network connectivity:

    With System Center 2012 View Logical network connectivity in the pane on the right.
    With System Center 2012 SP1 or
    System Center 2012 R2
    Under the physical network adapter, click Logical network connectivity.

    Notice the various kinds of information displayed, such as the list of IP subnets and VLANs that are available. With System Center 2012 R2, if you’ve added a top-of-rack (TOR) switch as a network service, port information that is provided by the switch might also be displayed.
  9. Review the list of logical networks, and take note of the following:

    • You might have to look fairly carefully at the entries in the list, because some of them might not actually be available for this host. The list is not limited to the logical networks with network sites that include the host group of this host. Instead, the list includes all the logical networks.

    • You might see some logical networks that appear to have been created automatically—this means that you added a host to VMM and the host didn’t already have logical networks assigned to its network adapters. However, automatic creation of logical networks depends on your global settings, as described in How to Configure Global Network Settings in VMM.

  10. Check the box next to each logical network that you want to assign to the physical adapter. For example, if you configured the BACKEND logical network in the Preparing the Fabric in VMM section, and the BACKEND logical network is available to the host group of your host, check the box next to BACKEND.

  11. If you’re running System Center 2012, to configure advanced settings, click Advanced, and view or modify the following:

    • The mode. Make sure you use the same mode that’s used by the physical switch port that the network adapter is connected to:

      Trunk mode In trunk mode, the different virtual machines that use the network adapter can use different VLAN IDs. Make sure that trunk mode is configured consistently across your hardware and software, including:

      - The port on the physical switch that the physical network adapter on the host is connected to
      - The port of the virtual switch

      When you configure trunk mode in VMM, either specify the VLAN IDs that the different virtual machines are using, or specify that you want to allow all VLAN IDs to be used.
      Access mode Use access mode when the physical network adapter is connected to a switch port that is also in access mode. Make sure the virtual machines that use the network adapter all use the same VLAN ID (the VLAN ID expected by the switch port).
    • The IP subnets and VLANs that are available for a given logical network on the network adapter. By default, for a selected logical network, the IP subnets and VLANs assigned to the network adapter are the ones that are configured to use that host group or are inherited through the parent host group.

      To select the available IP subnets and VLANs, click a logical network in the Logical network list. Then, use the Add and Remove buttons to configure which IP subnets and VLANs are assigned to the adapter.

      Note

      If no IP subnets or VLANs appear in the Available or Assigned columns, this tells you that for the selected logical network, there is no network site that is configured to use the host group or inherited by the host group. For more information about network sites, see Configuring Logical Networking in VMM Overview and How to Create a Logical Network in VMM.

      In the Logical network list, if the Unassigned option is available, you can view any VLANs that the physical network adapter is connected to, but are not included in a network site. You can either remove these VLANs from the network adapter, or you can include them in a network site.

Configure settings for external, internal, and private virtual networks

Use the following procedure to control the types of connectivity available to virtual machines by using External, Internal, or Private settings (more details about these settings are in the procedure). Also use this procedure to configure host access through VLANs. You configure these settings through a host property that in System Center 2012 is called a virtual network and in System Center 2012 SP1 and System Center 2012 R2 is called a virtual switch.

To configure settings for external, internal, and private virtual networks

  1. If you plan to apply the External setting, make sure you’ve done the steps in Assign logical networks to a physical network adapter on a host, earlier in this topic.

  2. In the VMM console, open the Fabric workspace.

  3. In the Fabric pane, expand Servers, expand All Hosts, and then locate and click the host group that contains the host.

  4. In the Hosts pane, click the host that you want to configure.

  5. On the Host tab, in the Properties group, click Properties.

  6. In the Host Name Properties dialog box, do the following:

    With System Center 2012 Click the Virtual Networks tab. Then, under Virtual Networking, click the virtual network that you want to configure, or click Add to add a new virtual network.
    With System Center 2012 SP1 or
    System Center 2012 R2
    Click the Virtual Switches tab. Then click an existing virtual switch, or click New Virtual Switch and then click New Standard Switch.

    If you do not want to apply each setting individually (that is, you do not want to use a standard switch), and you instead want to apply a logical switch to the network adapter, see the procedures in How to Configure Network Settings on a Host by Applying a Logical Switch in VMM.
  7. In the Name box, enter a name, or accept the default.

  8. In the Network binding list, click the network type. You can configure the following types:

    External Allows virtual machines to communicate with each other and with externally located servers, and optionally with the host operating system. You might use this setting to allow virtual machines to access a perimeter network and not expose the host operating system. An External network is bound to a physical network adapter.
    Internal Allows communication between virtual machines on the same host and between the virtual machines and the host. This setting is often used to build a test environment where virtual machines are connected to the host operating system, but not connected to external networks. An Internal network is not bound to a physical network adapter.
    Private Allows communication between virtual machines on the same host but not with the host or with external networks. This setting is often used to isolate virtual machines from network traffic in the host operating system and in the external networks. A Private network does not have a virtual network adapter in the host operating system, and is not bound to a physical network adapter.
  9. If you click External, do the following:

    1. In the Network adapter list, click the physical network adapter that you want to associate with the external virtual switch (or external virtual network, as it is called in System Center 2012).

    2. Review the Logical network field, which tells you which logical networks are assigned to the network adapter. To assign logical networks to a physical network adapter, see Assign logical networks to a physical network adapter on a host, earlier in this topic.

    3. If you’re running System Center 2012 SP1 or System Center 2012 R2, skip this step. Otherwise, to enable the host to use the virtual network to communicate with virtual machines and also with the external network, check Host access.

      Warning

      If you clear the Host access check box for the physical network adapter that is used for management, you may lose connectivity to the host.

    4. To access the host through a VLAN, check Access host through a VLAN (if available), and then select a VLAN number. The list that you see shows the VLANs that are included in the logical network and are assigned to the network adapter.

      Warning

      If you specify a VLAN for a single network connection to the host, network connectivity may be lost and you may lose the ability to manage the host. We recommend that you always use at least two physical network adapters on a host: one network adapter dedicated to remote management and communication between the host and the VMM server, and one or more network adapters dedicated to the external virtual networks that are used by virtual machines.

The following tips may also be useful:

Tip

Network optimizations: VMM can detect whether the operating system on your host provides the network optimizations called Virtual Machine Queue (VMQ) or TCP Chimney Offload. If VMM detects either of them, it displays a message saying Network optimization is available. Look for the message in the Host Properties dialog box, on the Virtual Networks tab (in System Center 2012) or the Virtual Switches tab (in System Center 2012 SP1 or System Center 2012 R2).

For more information, see Using TCP Chimney Offload and Using Virtual Machine Queue. For information about these network optimizations in the context of VMM, see the “Network Optimization Support” section in Configuring Virtual Networks in VMM (which describes the optimizations in an earlier version of VMM).

Tip

Compliance of network settings: You can use VMM to check on “compliance,” that is, whether the settings you configured on the host by using VMM are as expected, or whether they’ve been changed through some other interface. For example, you can see whether all the IP subnets and VLANs that are included in a network site in a logical network are assigned to a network adapter. For more information, see How to View Compliance Information for a Physical Network Adapter on a Host in VMM. If you have System Center 2012 SP1 or System Center 2012 R2, you might also want to see How to View Host Network Adapter Settings and Increase Compliance with Logical Switch Settings in VMM.

See Also

Configuring Networking in VMM
Configuring Hyper-V Host Properties in VMM
How to Configure Network Settings on a Host by Applying a Logical Switch in VMM
How to View Compliance Information for a Physical Network Adapter on a Host in VMM