What is Virtual Network?

• The process of combining hardware and software network resources and network functionality into a single, software-based administrative entity is called a virtual network (VNet)
• VNet is the interconnection between devices (i.e. VMs, virtual servers and others) in a virtualized computing environment
• A VNet is a network where connection between devices are done through software and wireless technology
• The Internet as a whole may be characterized as a virtual network!
• Virtual networking technology makes it possible to control one or more remotely located computers or servers over the internet

Virtual Network in Azure

• Azure Virtual Network (VNet) is the fundamental building block for networking in Azure (IaaS)
• VNet enables many types of Azure resources (i.e. Azure VM)to securely communicate:
  • with each other
  • internet
  • on-premises networks
• Details: https://docs.microsoft.com/en-us/azure/virtual-network/virtual-networks-overview

VNet concepts

• Network security groups: containes security rules to filter network traffic
• Address space:
  • an address space defines a range of discrete addresses, each of which may correspond to a network host, peripheral device
  • the amount of memory allocated for all possible addresses for a computational entity, such as a networked computer
  • an address space must be specified when creating VNet
• Subnets:
  • to segment the virtual network into one or more sub-networks
  • when creating VNet, a default subnet will be created by default
• Regions:
  • VNet is scoped to a single region/location
  • multiple VNets from different regions can be connected together using Virtual Network Peering