Paper: Top Seven Networking Concepts Every Virtualization Administrator Should Know – UPDATED

Dell has released a paper titled: “Top Seven Networking Concepts Every Virtualization Administrator Should Know“. The paper which contains 7 pages and is written by Scott D. Lowe, Founder and Managing Consultant, The 1610 Group. The paper discusses concepts that today’s modern VMware virtualization administrator needs to know to maximize overall system performance while controlling costs, some of the tips relate to other Hypervisor platforms as well. The paper is available for users after logging in with their Quest account, or by creating one.

Top Seven Networking Concepts Every Virtualization Administrator Should Understand:

  1. Networking in a Virtual Environment is Different from Networking in a Physical World – Networks in a virtual environment operate like those in a physical world, but as you start peeling back the virtualization layers, you find a shift in how network traffic itself flows around the network. A variety of mixed network traffic makes its way around the network and virtualization has fundamentally shifted the way traffic flows around it.
  2. The Type of Applications and Chosen Hypervisor Features Help Determine How Many Physical Network Interface Cards (NICs) are Enough – One question often asked by fresh virtualization admins is, “How many physical NICs are required to support the workloads and services necessary for high availability and workload migration?” The number depends on the types of applications being run, the hypervisor features chosen to deploy, and the desired level of redundancy.
  3. Understand the Different Network Adapters Available and Which Should be Used – There are feature benefits of the three available vSphere network adapters – E1000, VMXNET2 and VMXNET3 – yet the VMXNET3 network adapter provides best performance and require fewer resources from the vSphere host.
  4. Know The Basic Layers – Virtual admins should understand the basic concepts behind how the first three layers of the OSI networking model operate – physical layer, data link layer, network layer – and know what devices operate at each level. Additionally, in order to effectively troubleshoot network connectivity a virtual admin must be able to ‘subnet’ – identify when an IP address is local to a vSphere host or VM.
  5. The Role VLANs Play in a Virtual Environment – Often used to segment networks, VLANs have become more important for improving the overall security of an environment and for reducing the size of a network’s broadcast domain in order to improve the overall performance of the network.
  6. How VLANs extend into the Virtual Environment – Administrators can mimic the physical network by dedicating a single VLAN to a single network adapter in the host server, a method that doesn’t scale very far. A more common way to extend VLANs into the environment is through VLAN tagging and ‘trunking’ which offers significant flexibility to the virtual environment.
  7. The Difference Between the Standard Virtual Switch and vSphere Distributed Switch – The virtual environment can add administrative complexity to the technology management equation. The virtual switch (vSwitch) is a necessary part of the environment but must be individually configured on each vSphere host, resulting in a lot of effort. The new vSphere distributed switch (vDS) is a cluster-level object shared across all hosts that is easy to manage and significantly reduces administrative network burden.