cloudstack 笔记

23rfc

　　the Virtual Router provides many cool features like LoadBalancing, PortForwarding, (s)NAT, DHCP, VPN and so on.
　　Whena new network is created and being used, a Virtual Router is automatically launched to support these features.

　　Partof adding a zone is setting up the physical network. One or (in an advanced zone) more physical networks can be associated with each zone.The network corresponds to a NIC on the hypervisor host.Each physical network can carry one or more types of network traffic.The choices of traffic type for each network vary depending on whether you are creating a zone with basic networking or advanced networking.

　　

　　Whenbasic networking is used, there can be only one physical network in the zone.

　　

　　Whenend users run VMs, they generate guest traffic. The guest VMs communicate with each other over a network that can be referred to as the guest network. Eachpod in a basic zone is a broadcast domain, and therefore each pod has a different IP range for the guest network. The administrator must configure the IP range for each pod.

　　WhenCloudStack's internal resources communicate with each other, they generate management traffic. This includes communication between hosts, system VMs (VMs used by CloudStack to perform various tasks in the cloud), and anyother component that communicates directly with the CloudStack Management Server. You must configure the IP range for the system VMs to use.

　　Publictraffic is generated when VMs in the cloud access the Internet. Publicly accessible IPs must be allocated for this purpose. End users can use the CloudStack UI to acquire these IPs to implement NAT between their guest network and the public network, as describedin Acquiring a New IP Address.

　　

　　
Guest VMs have a name and group. VM names and groups are opaque to CloudStack and are available for end users to organize their VMs. Each VM can have three names for use in different contexts. Only two of these names can be controlled by the user:

• Instance name – a unique, immutable ID that is generated by CloudStack and can not be modified by the user. This name conforms to the requirements in IETF RFC 1123.
  
• Display name – the name displayed in the CloudStack web UI. Can be set by the user. Defaults to instance name.
  
• Name – host name that the DHCP server assigns to the VM. Can be set by the user. Defaults to instance name