Hyper-V Virtual Network Technology II

I. Function Description:

Customers want a simple way to seamlessly extend their data centers to the cloud. Currently, building such a seamless hybrid cloud architecture faces some technical challenges. Hyper-V network virtualization provides a virtual network independent of the underlying physical network. A virtual network consists of one or more virtual subnets. In this virtual network concept, the exact physical location of an IP subnet is decoupled from the virtual network topology. Therefore, customers can easily move their subnets to the cloud, while maintaining their existing IP addresses and topologies in the cloud, so that the existing service programs can continue to operate, instead of the physical location of the subnet. Hyper-V network virtualization enables the establishment of a seamless hybrid cloud.

In addition to hybrid clouds, many organizations are integrating their data centers and building private clouds to enjoy the efficiency and scalability brought by the cloud architecture. By separating the virtual network topology of the business department from the actual physical network topology, Hyper-V network virtualization can bring better scalability and higher efficiency to the private cloud. In this way, the business department can easily share an internal private cloud and be independent of each other. The data center operation team can flexibly deploy and migrate data in real time anywhere in the data center without server interruption, which can improve the operation efficiency and bring a more effective data center as a whole.

Hyper-V network virtualization provides virtual networks for virtual machines, just as hypervisor can provide virtual machines for the operating system. Network virtualization decouples the virtual network from the physical network infrastructure, and removes the limit of VLAN and Virtual Machine-configured Hierarchical IP Address allocation. This flexibility makes it easy for customers to move to The IaaS cloud, and allows host and data center administrators to manage their infrastructure more effectively while maintaining necessary multi-tenant isolation and security requirements, it also supports overlapping Virtual Machine IP addresses.

The main advantage of a workload owner is that the workload "Topology" can be moved to the cloud without changing its IP address or rewriting its application. For example, a typical layer-3 LOB application consists of a front-end layer, a business logic layer, and a database layer. Through policies, Hyper-V network Virtualization allows customers to load the entire or part of the three layers to the cloud, while maintaining the routing topology and IP address of the service program, that is, the virtual machine IP address ), you do not need to change the application.

For infrastructure owners, the extra flexibility of virtual machines allows them to move workloads anywhere in the data center without changing the virtual machine or reconfiguration the network. For example, Hyper-V network virtualization can achieve real-time cross-subnet migration, so that virtual machines can be migrated to any place in the data center in real time without service interruption. Originally, real-time migration was limited to the same subnet, thus limiting the locations where virtual machines can be located. Cross-subnet real-time migration allows administrators to integrate workload based on dynamic resource demands and energy efficiency, or adapt to infrastructure maintenance without interfering with normal operation of customer workload.

Ii. Practical Application

With the successful use of virtualized data centers, IT organizations and hosting providers provide hosting or physical server leasing providers) have begun to provide flexible virtual infrastructure, this allows you to easily provide server instances to customers as needed. This new service category is called infrastructure as a service (IaaS )". Windows Server 2012 provides all the platform capabilities required for company customers to build private clouds, and can transform to IT as a service operation mode. Windows Server 2012 allows hosts to build public clouds and provide customers with IaaS solutions. Microsoft provides powerful cloud solutions to manage Hyper-V network virtualization policies in conjunction with the system center.

Windows Server 2012 Hyper-V network virtualization provides policy-based and software-controlled network virtualization to reduce the management overhead faced by enterprises when expanding the dedicated IaaS cloud, it also provides more flexibility and scalability for VM instance management to achieve higher resource utilization. The IaaS solution that includes multiple virtual machines from Private clouds of different organizations or clouds hosted by different customers must be securely isolated. The current VLAN solution has obvious disadvantages in this case.

VLANCurrently, VLAN is a mechanism used by most organizations to support repeated use of address space and tenant isolation. A VLAN uses an explicit identifier (vlan id) in the Ethernet frame header. It relies on an Ethernet switch to forcibly isolate and limit the traffic of network nodes with the same vlan id. The main disadvantages of VLAN are as follows:

• Whenever a virtual machine or isolation boundary is moved to a dynamic data center, the re-configuration of the production switch is complicated, which increases the risk of unexpected interruptions.

• The scalability is limited because the VLAN IDs supported by the standard switch cannot exceed 1000 and the maximum number is 4094.

• Limited by an IP subnet, this limits the number of nodes in a single VLAN and limits the placement of multiple virtual machines based on physical locations. Even if a VLAN can be expanded across multiple networks, the entire VLAN must all be located on the same subnet.

IPAddress AllocationIn addition to the disadvantages of VLAN presentation, virtual machine IP Address Allocation also brings about the following problems:

• The physical location in the network infrastructure of the data center determines the IP address of the virtual machine. Therefore, to move to the cloud, you usually need to rename the service workload to change the IP address ).

• Policies are bound to IP addresses, such as firewall rules, resource discovery, and directory services. To change the IP address, you must update all related policies.

• Virtual Machine deployment and traffic isolation depend on the topology.

When the data center network administrator plans the physical layout of the data center, they must determine the physical location and route of the subnet. These decisions are based on IP and Ethernet technologies that affect these IP addresses: virtual machines allowed to run on specific servers or server blades connected to a specific rack in the data center. When you configure and place a virtual machine in the data center, the virtual machine must comply with the selection and restrictions on IP addresses. Therefore, the Data Center Administrator usually assigns a new IP address to the VM. The problem with this requirement is that, in addition to being an address, an IP address also has associated semantic information. For example, a subnet may contain a given service or be located in a different physical location. Firewall Rules, access control policies, and IPsec security associations are usually associated with IP addresses. Changing the IP address forces the Virtual Machine owner to adjust all policies based on the original IP address. Due to the high overhead of this numbering operation, many enterprises only deploy new services to their cloud, leaving old applications unchanged. Hyper-V network virtualization decouples the virtual network of the customer's virtual machine from the physical network infrastructure. Therefore, it allows the customer's Virtual Machine to maintain the original IP address, and allows the Data Center Administrator to place the customer's Virtual Machine anywhere in the data center without re-configuring the physical IP address or vlan id. The main functions are described in the next section.

Iii. Important functions:

Important features, advantages, and capabilities of Hyper-V network Virtualization in Windows Server 2012 are summarized as follows:

1Allows flexible workload placement-network isolation without VLAN and IP address reuse.
Hyper-V network virtualization decouples the customer's virtual network from the host's physical network infrastructure, so it provides free workload placement in the data center. VM workload placement is no longer limited by IP Address allocation or VLAN isolation requirements of physical networks, because it is executed on a multi-tenant virtual policy defined by software in a Hyper-V host.
Virtual machines of different customers with overlapping IP addresses can now be deployed on the same host server without tedious VLAN configuration or violation of the IP address hierarchy. This simplifies the movement of customer workloads to shared IaaS hosting providers, allowing customers to move these workloads without changing the IP address of virtual machines. Hosting providers support a large number of customers who want to extend their existing network address space to a shared IaaS data center. This is a complex operation for each customer to configure and maintain an independent VLAN, to ensure the coexistence of overlapping address spaces. Hyper-V network virtualization makes it easier to support overlapping addresses and reduces the need for network reconfiguration by hosting providers.
In addition, it can also maintain and upgrade the physical infrastructure without causing the customer's workload to stagnate. With Hyper-V network virtualization, virtual machines on a specific host, Rack, subnet, VLAN, or cluster can be moved without re-numbering or reconfiguration.

2,It is easier to move workload to the shared IaaS cloud.
With Hyper-V network virtualization, the IP address and Virtual Machine configurations remain unchanged. This allows IT organizations to move their workloads from their data centers to shared IaaS hosting providers with minimal workload or reconfiguration of their infrastructure tools and policies. When two data centers are connected, IT administrators can continue to use their tools without reconfiguration.

3,Real-time cross-subnet migration
Traditional real-time migration of Virtual Machine workload has been limited to the same IP subnet or VLAN, because cross-subnet requires the virtual machine's customer operating system to change the IP address. Address changes interrupt existing communication and interfere with services running on virtual machines. With Hyper-V network virtualization, workloads can be migrated from servers running Windows Server2012 In the subnet to servers running Windows Server 2012 in different subnets in real time, instead of changing the IP address of the workload. Hyper-V network virtualization ensures that the location changes of virtual machines caused by real-time migration are updated and synchronized on hosts that have continuous communication with the migrated virtual machines.

4,Easier management of decoupling servers and network management
The server workload arrangement is simplified because the workload migration and arrangement are independent of the underlying physical network configuration. Server administrators can focus on service and server management, while network administrators can focus on the overall network infrastructure and traffic management. This allows the data center server administrator to deploy and migrate virtual machines without re-numbering the virtual machines. This reduces overhead because Hyper-V network Virtualization allows virtual machines to be placed independently of the network topology, reducing the need for network administrators to participate in the placement process that may change the isolation boundary.

5,Simplify the network and improve the utilization of server or network resources
The rigidity of VLAN and the dependency of virtual machines on the physical network infrastructure may lead to over-configuration and insufficient utilization. By breaking this dependency, the flexibility of Virtual Machine workload scheduling can simplify network management and improve the utilization of server and network resources. Note: Hyper-V network virtualization supports VLANs in the background of a physical data center. For example, a data center may want all Hyper-V network virtualization traffic to be performed in a specific VLAN.

6,Compatible with existing infrastructure and emerging technologies
Hyper-V network virtualization can be deployed in the current data center, but it is also compatible with the emerging "flat network" technology.

7,Creating a foundation for interoperability and ecosystem preparation
Hyper-V network virtualization supports multiple configurations for communication with existing resources, such as cross-organization connections, storage area networks (SAN), and non-virtualized resource access. Microsoft is committed to working with ecosystem partners to support and improve Hyper-V network Virtualization in terms of performance, scalability, and management.

8,Use Windows PowerShell and WMI
Hyper-V network virtualization supports Windows PowerShell and Windows Management Instrumentation (WMI) to configure network virtualization and isolation policies. The Windows PowerShell cmdlet of Hyper-V network Virtualization allows administrators to set up command line tools or automated scripts to configure, monitor, and troubleshoot network isolation policies.

 

 

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