What is Virtual IP?

In bridged network environments, a virtual IP address (VIP) provides network services such as serving as an elastic IP address (EIP), port forwarding, load balancing, IPsec tunneling. When a VIP provides the preceding network services, packets are sent to the VIP and then routed to the destination network where VM instances are located.
  • VIPs created from a public network can provide network services such as EIP and load balancing for flat networks.
  • VIPs created from a public network can provide network services, such as EIP, port forwarding, load balancing, and IPsec tunnel, for VPC networks.
  • VIPs created from a VPC network can provide load balancing services for VPC networks.
  • VIPs created from a flat network can provide network services, such as EIP and load balancing, for flat networks.

You can use a VIP to provide performance-shared load balancing services. A performance-shared load balancer uses a VPC vRouter to provide load balancing services. Traffic is distributed to backend servers by the VPC vRouter. If the VPC vRouter is providing multiple services, the load balancing service shares the performance of the VPC vRouter along with other services.



Concepts

  • Public VIP: VIPs created from a public network. You can manually create a public VIP or use a public VIP automatically created after a VPC vRouter creation.
    • A public VIP can provide network services, such as EIP and load balancing, for flat networks. A public VIP can also provide network services, such as EIP, port forwarding, load balancing, and IPsec tunnel, for VPC networks.
    • You can use a public VIP to simultaneously provide port forwarding, load balancing, and IPsec tunnel services. However, you cannot specify the same port number for different services. You can also use a public VIP to provide one service for multiple VM instances.
    • A public VIP supports QoS, monitoring data, performance TOP 5, performance analysis, alarm, and other features.
  • VPC VIP: VIPs created from a VPC network. A VPC VIP can only be manually created.
    • A VPC VIP can provide load balancing services for VPC networks.
    • VPC VIPs do not support QoS, monitoring data, performance TOP 5, performance analysis, and alarm features.
  • Flat network VIP: VIPs created from a flat network. You can manually create a flat network VIP or use a flat network VIP automatically created after a VPC vRouter creation.
    • A flat network VIP provides network services, such as EIP and load balancing, for flat networks.
    • A flat network VIP supports QoS, monitoring data, performance TOP 5, performance analysis, alarm, and other features.
  • Custom VIP: manually created VIPs. You can customize a public VIP, VPC VIP, and flat network VIP based on your needs.
    • One custom public VIP can only be applied to one EIP instance.
    • Custom VIPs cannot be used across VPC vRouters.
    • When you use the EIP, port forwarding, load balancing, or IPsec tunnel services, you can select Create VIP to create a new VIP, or you can select Use Existing VIP to provide the services.
  • System VIP: VIPs automatically created by using the L3 network attached to VPC vRouters after the VPC vRouter creation. System VIPS can be categorized into public VIPs and flat network VIPs.
    • A system VIP belongs to only one VPC vRouter. When you attach a public network to a VPC vRouter, the Cloud will automatically create a system VIP. This VIP is the default IP address of the vRouter in the network.
    • By default, the system VIPs created from public networks are used to provide the source network address translation (SNAT) service.
    • When you use the EIP, port forwarding, load balancing, or IPsec tunnel service, you can select Use Existing IP to provide the services.