Floating public IP
Floating IPs are public IPv4 addresses that enable access to the Internet from an instance inside a tenant. Two floating IPs are accessible from each tenant by default, which is considered sufficient for most networking situations and workloads.
IPv4 addresses is a scarce resource, so rather than allocating a separate address to each server, one IPv4 address is used for server management through a bastion host and the other for service delivery through a load balancer or reverse proxy server. For details on how to implement and configure such a network, please see Configure network
Initially, the floating IPs need to be allocated to the tenant from a common address pool. A floating IP address has the following properties:
It can be used immediately: No routing information needs to be exchanged - the mapping between the floating IP address and the VM (its private address) is done by an instance of Contrail L3 agent in the DT Cloud Services cloud.
It can instantly be re-assigned and re-allocated within the same site by OpenStack commands.
More information about the floating IP concept can be found under Concepts in Floating IP