Configuring VM Networks in VMM Illustrated Overview

Updated: May 13, 2016

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

In Virtual Machine Manager (VMM) in System Center 2012 Service Pack 1 (SP1) and System Center 2012 R2, networking includes a number of enhancements that provide you with greater flexibility in configuring networks in a virtualized environment. This overview focuses on one of the enhancements, virtual machine networks (VM networks), although it also shows logical networks.

Logical networks, which were introduced in System Center 2012 and are also found in System Center 2012 SP1 and System Center 2012 R2, are named networks that serve particular functions in your environment. For example, you could have logical networks with names such as “Backend,” “Frontend,” or “Backup.” Logical networks are illustrated in Figure 1 and Figure 6 in this topic.

Other figures in this topic show VM networks, which are found in VMM in System Center 2012 SP1 and System Center 2012 R2. VM networks increase the number of ways you can configure networking for your virtual machines. The illustrations show four different ways that a VM network can be configured on top of a logical network.

The following table describes the illustrations in this topic.

For information about how to configure VM networks, see How to Create a VM Network in VMM in System Center 2012 SP1 or How to Create a VM Network in VMM in System Center 2012 R2.

For illustrations of logical switches, see Configuring Ports and Switches in VMM Illustrated Overview.

For more details about networking in VMM, see the following networking overviews:

• Configuring Logical Networking in VMM Overview

• Configuring Load Balancing in VMM Overview

• Configuring Ports and Switches for VM Networks in VMM

• Configuring VM Networks and Gateways in VMM

The following illustration shows a logical network in VMM in System Center 2012, System Center 2012 SP1, or System Center 2012 R2. For some networking elements, fictitious names such as “Contoso1” are included to help illustrate the purpose of those elements.

Figure 1 Logical network

This illustration shows how a logical network in VMM is a container for network sites (also called logical network definitions) and for IP subnet information, virtual local area network (VLAN) information, or both. It also shows how host groups in VMM can be associated with a network site and how IP address pools can be assigned to subnets within the logical network.

In the preceding illustration, the names of elements that you configure by running a wizard or opening a property sheet are shown in bold text, and elements that are on a page of the wizard or on a tab of the property sheet are shown without bold text.

For an illustration that shows the underlying network object model for logical networks, see Figure 6, Network object model for logical networks.

The illustrations in this section show how VM networks can be configured on top of logical networks in VMM.

The following illustrations show four different ways that VM networks can be configured on top of logical networks in VMM:

• VM networks configured with network virtualization: Multiple VM networks can be configured on top of one logical network.

• VM networks in a VLAN-based configuration: Networks that use familiar virtual local area network (VLAN) technology for network isolation can be managed as they are—with one VM network for each network site (and VLAN) in the configuration.

• VM network that provides direct access to the logical network with no isolation: One VM network can provide direct access to the logical network, with no isolation.

• VM networks configured with an external network service: Settings configured with a network service, such as a vendor network-management console that uses a forwarding extension, can be imported into VMM. With System Center 2012 R2, such settings can also be exported from VMM to the network service.

VM networks configured with network virtualization

The following illustration shows VM networks that are configured with network virtualization in VMM in System Center 2012 SP1 or System Center 2012 R2. For some networking elements, fictitious names, such as “AdventureWorks” and “Contoso1,” are included to help illustrate the purpose of those elements.

Figure 2 VM networks with network virtualization

Network virtualization extends the concept of server virtualization to make it possible for you to deploy multiple VM networks on the same logical network. In the illustration, the “AdventureWorks” VM network is configured on top of the logical network called “Contoso1.” As indicated in the illustration, additional VM networks can be configured on top of the same logical network, so that additional tenants, clients, or customers can each have their own network and choose their own IP addresses, regardless of the IP addresses that are used in other VM networks.

In the preceding illustration, the names of elements that you configure by running a wizard or opening a property sheet are shown in bold text, and elements that are on a page of the wizard or on a tab of the property sheet are shown without bold text.

For an illustration that shows the underlying network object model for this configuration, see Figure 7, Network object model for VM networks configured with network virtualization.

In System Center 2012 SP1 and System Center 2012 R2, many of the VMM networking enhancements are based on Hyper-V network virtualization, which was introduced in Windows Server 2012. To understand these networking enhancements, it can be useful to review the illustrations and descriptions (especially the first illustration) of Hyper-V network virtualization in Hyper-V Network Virtualization technical details.

VM networks in a VLAN-based configuration

The following illustration shows VM networks in a VLAN-based configuration, that is, where VLANs already exist in the physical and logical networks. For some networking elements, fictitious names, such as “Contoso2” and “VLAN_1” are included to help illustrate the purpose of those elements.

Figure 3 VM networks in a VLAN-based configuration

In the scenario that is illustrated here, the VLANs exist for a specific purpose, such as isolation, and not for broadcast boundaries only. The illustration shows two VM networks that have been created, to match the two VLANs in the underlying physical and logical networks. With more VLANs, more VM networks could be created—typically, one VM network per VLAN.

In the preceding illustration, the names of elements that you configure by running a wizard or opening a property sheet are shown in bold text, and elements that are on a page of the wizard or on a tab of the property sheet are shown without bold text.

For an illustration that shows the underlying network object model for this configuration, see Figure 8, Network object model for VM networks in a VLAN-based configuration.

VM network that provides direct access to the logical network with no isolation

The following illustration shows a VM network that is configured to provide direct access to the underlying logical network. For some networking elements, fictitious names, such as “Contoso1” and “Internet_connection1,” are included to help illustrate the purpose of those elements.

Figure 4 VM network that provides direct access to the logical network

A VM network that provides direct access to the logical network contrasts with VM networks that use network virtualization. Another way of describing this is to say that a VM network that provides direct access provides “no isolation,” while VM networks that use network virtualization provide isolation from the logical network and from each other. On each logical network, you can have only one VM network that is configured with No isolation. However, on a logical network that allows network virtualization, you can have one VM network with no isolation and other VM networks with isolation (that is, with network virtualization).

In the configuration shown in the illustration, when a virtual machine is deployed, the choice of the IP subnet/VLAN pair is made by VMM, based on the location (the host or the cloud) where you are deploying the virtual machine.

In the preceding illustration, the names of elements that you configure by running a wizard or opening a property sheet are shown in bold text, and elements that are on a page of the wizard or on a tab of the property sheet are shown without bold text.

For an illustration that shows the underlying network object model for this configuration, see Figure 9, Network object model for a VM network that provides direct access to the logical network.

VM networks configured with an external network service

The following illustrations show a type of external network service: a vendor network-management console that has been used to configure settings on a forwarding extension (for example, settings for logical networks, network sites, and VM networks). The illustrations also show a VMM management server that has been configured to work with the vendor network-management database. For some networking elements, fictitious names, such as “External1” and “AdventureWorks,” are included to help illustrate the purpose of those elements.

Figure 5a shows that with VMM in System Center 2012 SP1, the VMM management server imports settings from the vendor network-management database (but cannot export settings). This contrasts with Figure 5b, later in this section.

Figure 5a VM networks configured with a vendor network-management console (with VMM in System Center 2012 SP1)

Figure 5b shows that with VMM in System Center 2012 R2, the VMM management server and the vendor network-management database can both send and receive information about settings.

Figure 5b VM networks configured in coordination with a network service (with VMM in System Center 2012 R2)

As the preceding illustrations indicate, the VMM management server contains the appropriate provider software (which you must install). Although the illustration shows a particular configuration of VM networks as an example, the VM network configuration will reflect any configuration that you create. With the configuration that is shown in both illustrations, if network settings have been configured on the network-management console, they do not have to be configured again in VMM. Instead, the settings automatically appear in VMM.

For an illustration that shows the underlying network object model for this configuration, see Figure 10, Network object model for VM networks configured with an external network service.

The following illustration shows the network object model for logical networks in VMM in System Center 2012, System Center 2012 SP1, and System Center 2012 R2. The illustration shows the relationships among network objects only, rather than indicating information about the wizards and property sheets through which the objects are configured in the VMM console. The illustration can be especially useful if you are learning about configuring VMM through Windows PowerShell scripts, which reflect the network object models directly.

For some objects, sample names such as “Contoso1” and “Building1” are included to help illustrate the purpose of those objects. (The object labeled “Network site” is also known as a “logical network definition.”)

Figure 6 Object model for logical networks

The following key explains the notations on the arrows:

• 1-1 means “one-to-one.”

• 1-M means “one-to-many.”

• M-M means “many-to-many.”

In the preceding illustration, bold text is used for each VMM object name, regardless of how that object is configured through the VMM console.

For an illustration of logical networks that is based on how they appear in the VMM console, see Figure 1, Logical networks in VMM.

The following illustrations show the network object models for logical networks and VM networks in VMM in System Center 2012 SP1 and System Center 2012 R2. These illustrations show the relationships among network objects only, rather than indicating information about the wizards and property sheets through which the objects are configured in the VMM console. The illustrations can be especially useful if you are learning about configuring VMM through Windows PowerShell scripts, which reflect the network object models directly.

Network object model for VM networks configured with network virtualization

The following illustration shows the network object model for VM networks that are configured with network virtualization.

For some objects, sample names such as “AdventureWorks” and “Contoso1” are included to help illustrate the purpose of those objects.

Figure 7 Object model for VM networks configured with network virtualization

As indicated in the illustration, the IP addresses on the VM network are also called the “customer address (CA) space” because these IP addresses are used by customers (or clients or tenants). The IP addresses on the logical network are also called the “provider address (PA) space” because these IP addresses are used by providers (or hosters).

The notation 1-M means “one-to-many.”

In the preceding illustration, bold text is used for each VMM object name, regardless of how that object is configured through the VMM console.

For an illustration of this configuration that is based on how it appears in the VMM console, see Figure 2, VM networks configured with network virtualization.

Network object model for VM networks in a VLAN-based configuration

The following illustration shows the network object model for VM networks in a VLAN-based configuration.

Figure 8 Object model for VM networks in a VLAN-based configuration

The following key explains the notations on the arrows:

• 1-1 means “one-to-one.”

• 1-M means “one-to-many.”

• M-1 means “many-to-one.”

In the preceding illustration, bold text is used for each VMM object name, regardless of how that object is configured through the VMM console.

For an illustration of this configuration that is based on how it appears in the VMM console, see Figure 3, VM networks in a VLAN-based configuration.

Network object model for a VM network that provides direct access to the logical network

The following illustration shows the network object model for a VM network that provides direct access to the logical network, with no isolation. This is the simplest configuration, where the VM network is the same as the logical network on which it is configured.

Figure 9 Object model for a VM network that provides direct access to the logical network

The following key explains the notations on the arrows:

• 1-1 means “one-to-one.”

• 1-M means “one-to-many.”

In the preceding illustration, bold text is used for each VMM object name, regardless of how that object is configured through the VMM console.

For an illustration of this configuration that is based on how it appears in the VMM console, see Figure 4, VM network that provides direct access to the logical network with no isolation.

Network object model for VM networks configured with an external network service

The following illustration shows the network object model for VM networks that are configured with a network service, such as a vendor network-management console that works with a forwarding extension. This configuration uses a virtual switch extension manager to enable communication with the vendor network-management console.

Figure 10 Object model for VM networks configured with a network service such as a vendor network-management console

The following key explains the notations on the arrows:

• 1-1 means “one-to-one.”

• 1-M means “one-to-many.”

In the preceding illustration, bold text is used for each VMM object name, regardless of how that object is configured through the VMM console.

For an illustration of this configuration that is based on how it appears in the VMM console, see Figure 5, VM networks configured with an external network service.

How to Create a VM Network in VMM in System Center 2012 SP1
How to Create a VM Network in VMM in System Center 2012 R2
Configuring Logical Networking in VMM Overview
Configuring VM Networks and Gateways in VMM
Configuring Ports and Switches for VM Networks in VMM
Common Scenarios for Networking in System Center 2012 SP1 and System Center 2012 R2