What is network virtualization?

The purpose of a data center is only to deploy applications. Applications deployed have automated business processes that better serve customers and enter the new market ...... You understand my consciousness. These are all about applications.

Server Virtualization

An application consists of computing resources and network resources. Both are indispensable; they are symbiotic. However, in the past few decades, half (Computing) has been ahead of the other half (network) for many years. Computing and networks form asymmetric symbiosis.

For example, a powerful automation software on general hardware can deploy computing resources (virtual servers) of applications in seconds-server virtualization. On the other hand, virtual networks still need to be manually prepared on specific hardware using the keyboard and command line. At the same time, the application deployment has to be delayed for several days, weeks, or even longer until the network resources are finally ready.

Server virtualization also makes computing resources have many amazing features. For example, mobility, snapshots, and one-click disaster tolerance. On the other hand, network resources do not have the same capabilities. No mobility-network configurations are bound to hardware. The snapshot of the network architecture of the application is also impossible, because the network configuration is in a large number of independent network devices (physical and virtual ). The Network Architecture (Disaster Tolerance) of application reconstruction in the second data center is unreliable without the same automation, mobility, and snapshot. The computing of Applications With virtualization capabilities is partly slowed down by non-virtualized networks, and it is difficult to achieve full potential. Network virtualization is a solution that symmetrical the symbiotic relationship between computing and networks. With the help of network virtualization, the preparation of Virtual Network Resources for applications will be consistent with that of virtual computing resources, with the same level of speed, automation, and mobility. Through server and network virtualization, computing resources and network resources will work in symmetric mode and be deployed synchronously, rather than one other. The application is completely decoupled through full automatic configuration and real movement.

What is virtualization?

Virtualization is the basic rule for decoupling infrastructure services from physical resources of operational services. The services we want to use (such as computing and network) are not described, identified, or strictly bound to any physical resources. Instead, a service is described as a data structure that exists completely on the software abstraction layer, so that the service can be rebuilt on any physical resource that runs the virtualization software. The service lifecycle, identity, location, and configuration attributes all exist in the software and have API interfaces. This enables all the potential for automated configuration. A typical example is server virtualization. The properties of physical servers are decoupled and re-represented as vCPU, vRAM, and vNIC In the virtualization software (hypervisor, in a few seconds, you can combine these attributes to produce an independent virtual server. Decoupling and automation through server virtualization can also make virtual networks have these features through network virtualization.

What is the network?

Virtual machines supporting applications often need to be able to connect to other virtual machines and the external world (WAN/Internet) securely and load balancing networks (switching and routing ). The first network device attached to the virtual machine is the software virtual switch in the hypervisor. The "network" we want to virtualize is the complete virtual machine visible to the L2-L7 service and all the network configuration States required to deploy the Application Network Architecture (layer n, etc ). Virtual networks are called virtual networks.

Through server virtualization, virtual servers have been completely decoupled from physical servers. On the other hand, virtual networks are not completely decoupled from physical networks. Therefore, the necessary configurations of the Virtual Network of the application must be carefully planned on many physical and virtual switches, as well as L4-L7 service facilities. Despite the best efforts of server virtualization, applications are still bound to hardware.

Network virtualization aims to take over all network services, features, and necessary configurations of the virtual network for applications (VLANs, VRFs, firewall rules, Server Load balancer pools & VIPs, IPAM, routing, isolation, multiple tenants) -- decouples all these features from the physical network and migrates them to the virtualization software layer to achieve automation.

The virtual network is completely decoupled, and the physical network configuration is simplified to provide packet forwarding service between hypervisor. The implementation details of physical packet forwarding are separated from the virtual network. Virtual networks and physical networks can evolve independently. The characteristics and capabilities of virtual networks evolve at the speed of the Software Release Cycle (month. Physical network packet forwarding evolves at the speed of the hardware release cycle (year. Packet forwarding is not a problem of application deployment. The current physical switch is very good, and the intensive line rate of the hardware-implemented standard IP protocol (OSPF, BGP) can reach 10/40/100G. Network virtualization mainly involves network rules, features, and manual deployment of services that build visible network architectures of application computing resources (virtual machines.

Network Virtualization

Network virtualization reconstructs the L2-L7 network services necessary to deploy the virtual network of the application, which also manages the virtual machine of the application-hypervisor kernel and programmable Virtual Switching. Similar to server virtualization rebuilding vCPU, vRAM, and vNIC-network virtualization software rebuilding logical exchange, logical routing (L2-L3), logical load balancing, logical firewall (L4-L7 ), in this way, virtual computing can be combined with any topology to represent a complete L2-L7 virtual network topology. All necessary configurations of the virtual network can be configured at the software Virtual Switching layer through APIS. The command line configuration for each application is no longer needed. The physical network provides a general underlying layer for packet forwarding. The programmable Virtual Switching layer provides a complete set of virtual network features and achieves isolation and multi-tenant.

Server and network Virtualization

Through Network virtualization, the virtual network can be completely configured using software APIs in the software, with the same speed and flexibility as server virtualization, so that their pace is consistent. Software tools used to configure application virtual machines can be used to configure computing and networks (using templates) at the same time. Next, verify the entire application architecture-computing and network together. Next, we will not just take snapshots of virtual machines, but take a snapshot of the entire application architecture (computing and network) and transfer a copy to the disaster recovery site-one-click disaster recovery standby. The final application network has the same mobility as computing, and runs as fast as it does. Because of server virtualization, network virtualization is reasonable. Computing and networks have a symbiotic relationship, and they should be deployed in a symmetric synchronous manner. This is obvious.

Original article: http://bradhedlund.com/2013/05/28/what-is-network-virtualization/