Computer Science Computing Systems virtual machine

System Virtual Machine

  • Hypothetical machine
  • Designed to contain important features of real computers

Network Connections

  • Every VM has a vNIC (virtual NIC)
  • Maximum number of vNICs depends on limits imposed by hypervisor
  • Networking modes
    • Bridged
      • vNIC accesses physical network using host machine's NIC
      • Obtains own IP address, default gateway, and network mask from DHCP server on physical LAN
      • Appears to other nodes as a regular client/server on the network
    • NAT
      • vNIC relies on host machine to act as NAT device
      • Obtains IP address from host
      • Hypervisor acts as a DHCP server
      • Other nodes on network won't have direct access
        • Must go through host
    • Host-only
      • VMs on one host can exchange data with each other and the host
      • Cannot communicate to nodes outside the host
      • Never receive or transmit data with host's physical NIC