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Floating IPs

Service description

Floating IPs are a feature of Compute service that allows for dynamic assignment of public IP addresses to instances (virtual machines) within a private network. Floating IPs allow instances (virtual machines) within a private network to be accessible from external networks, such as the internet. This is achieved through a mechanism called Network Address Translation (NAT).

Features

  • Public accessibility, so that floating IPs can be assigned to instances to provide external connectivity by associating them with a public network (this is useful for accessing instances remotely, hosting web services, or providing public APIs)
  • Dynamic sssignment, so that floating IPs can be dynamically associated with or disassociated from instances (this allows for flexible management of public access, as the IP can be moved between instances as needed)
  • One-to-One NAT, Network Address Translation (NAT) for mapping the floating IP to the private IP of the instance (this means that traffic sent to the floating IP is automatically forwarded to the corresponding private IP of the instance)
  • Security, floating IPs do not bypass security group rules or firewall settings (access to instances via floating IPs is still subject to the security policies defined for the instance and network)
  • Limited resource, as a finite resource, floating IPs are limited by the available public IP addresses in the external network
  • Integration with load balancers, so that floating IPs can be used in conjunction with load balancers to provide a single public entry point that distributes incoming traffic across multiple instances

Key concepts

How it works

There are two types of networks in your cloud project; private networks, which are used for communication between instances, and public networks, which are used for external access. Public networks are often connected to the internet and have a pool of public IP addresses. This pool of addresses is the floating IP pool.

  1. The floating IP pool is made available to projects. Quotas limit the number of floating IPs that each project can use.
  2. When you want to make an instance accessible from the external network, you allocate a floating IP from the pool and associate it with the instance. This creates a one-to-one NAT (Network Address Translation) mapping between the floating IP and the private IP of the instance.
  3. With the floating IP associated, the instance can be accessed using the public IP address from outside the private cloud network. Incoming traffic to the floating IP is automatically forwarded to the private IP of the instance.
  4. You can disassociate floating IPs from instances when they are no longer needed for external access. The disassociated IPs are returned to the floating IP pool and can be reused by other instances within the project.
  5. Access to instances via floating IPs is still governed by security group rules and firewall settings. You need to ensure that the appropriate ports and protocols are allowed for the services you want to expose.

Floating IPs console

Command line tools

API methods

See also