Network Virtualization in Cloud Computing
Network Virtualization:
Virtual machine (VM) is the new It approach to use within the data center. The physical server platform is no more the fundamental constituent but is rather made up of various rational resources which are accumulated in the pool of virtual resources. Network designers can no more delay their design at the network interface card (NIC) level, but requires allowing for the server platforms network particulars like virtual switches (vSwitches). In network virtualization, multiple virtual networks run with the help of a physical network. Infrastructure administration amalgamation turns out to be more significant in this environment as the inter-relations between functions and appliances are tougher to manage and control.
Network virtualization comprises rationally grouping and segmenting physical networks into distinct rational units known as ‘virtual networks’ and forming them to act as one or multiple separate networks. It permits multiple virtual networks to share network resources. In a virtual data center (VDC), network virtualization comprises the virtualization of both VM and physical networks. The physical network may consist of network routers, hubs, switches, repeaters, adapters, and bridges. The physical network provides connectivity:
1. Among physical servers.
2. Between physical servers and clients
3. Between physical servers and storage systems.
Tools used in Network Virtualization:
Network virtualization is operated by a physical switch operating system (OS) and hypervisor. These kinds of software permit an administrator to develop virtual networks on VM and physical networks. A physical switch controls an operating system that executes network traffic switching.
The operating system should have network virtualization functionality to develop a virtual network on the switch. The hypervisor has integral networking and network virtualization functionalities. Third-party software offers these functionalities, which might be deployed on the hypervisor. Subsequently, the third-party software module substitutes the local networking functionality of the hypervisor.
Components of Network Virtualization:
There are two main components of network virtualization.
- Virtual Switches
- Virtual LAN
Virtual Switch:
Virtual switch is like a logical switching built into VMware so that a virtual machine network can be managed as per the requirement. Virtual switches act as interfaces between the virtual ethernet and the physical ethernet. It develops a VM network and supports the ethernet protocol as shown below figure:
They offer association to virtual NICs and send VM traffic. They also manage storage, administration, and VM migration traffic to and from the hypervisor kernel. Physical adaptors like converged network adapters (CNA), NIC and HBA facilitate physical servers to associate with physical networks. They send hypervisor VM traffic to and from a physical network.
Virtual switches control both VM traffic and hypervisor kernel traffic. Distinct kinds of ports are configured on a virtual switch for distinct kinds of traffic. Conversely, multiple virtual switches can be constructed, each with its virtual port. Virtual ports are categorized as uplink ports, hypervisor kernel ports and VM ports:
1. Uplink ports join a virtual switch to the physical NICs of the physical server where the virtual switch resides. A virtual switch may transport information to a physical network when one or more physical NICs are connected to its uplink port.
2. VM ports permit virtual NICs to link to a virtual port.
3. A hypervisor kernel enhances the hypervisor kernel to link to a virtual switch.
Virtual LAN:
A VLAN is a rational network constructed on a LAN or across multiple LANs. It consists of virtual or physical switches. VLAN permits you to have discrete LANs amongst ports on a similar switch. Every network is connected to a switch with the help of routers shown below figure:
A VLAN permits conversion among a cluster of nodes based on the performing needs of a corporation, independent of the position of nodes in the network. All nodes in a VLAN can be linked to LAN or distributed across multiple LANs. The VLAN skill may split a bulky LAN into lesser virtual LANs or merge divided LANs into one or more virtual LANs. The membership of a VLAN can be classified in various ways:
1. Port-based: Various port numbers are provided as per the services provided in the network. So, the port number of the same network is diverted as per the number so there is no conjunction in the network.
2. Portocol-based: In this type of VLAN, traffic is handled based on the protocol used in the network. Traffic following the same protocol will be diverted in the same network.
3. MAC-layer clustering: In VLAN at layer-2, vSwitches pass traffic to the MAC address of the connecting device. A large table of MAC addresses is stored in the memory for incoming packets. If the virtual port number on the virtual switch isn’t known, even then traffic will be handled easily.
4. Network-layer clustering: VLAN helps to create multiple layer 3 networks on a single physical network, for handling various virtual networks.
5. Multicast Grouping: VLAN helps to reduce traffic in the network by forming various broadcast domains that divide the whole network into smaller networks. Individual networks can then easily manage.
6. Policy Grouping: Traffic in VLAN is managed as per the various policies of network security.
Benefits of network virtualization:
1. Reduction of Hardware Expense: You may naturally save plenty of funds by minimizing hardware expenses using virtualization.
2. Energy Expense: Many businesses have discovered that virtualization has minimized the overall electricity utilization for server computers by around 80%. This is the effect of using minimum computer hardware to perform more work.
3. Recoverability: One of the prevalent advantage of virtualization isn’t the saving of expense, but the capability to swiftly recover from hardware malfunctions.
4. Disaster Recuperation: The most significant advantage of virtualization appears when an actual disaster recuperation condition occurs. You have to reconstruct a single host computer and reorganize the hypervisor software. You may effortlessly reinstate the backup of virtual machines from the tape and after resuming the virtual machines, it’ll work.
