Oracle Cloud Infrastructure Documentation

Public IP Addresses

Describes how to manage public IPv4 addresses on instances in a virtual cloud network (VCN).

A public IP address is an IPv4 address that is reachable from the internet. If a resource in your tenancy needs to be directly reachable from the internet, it must have a public IP address. Depending on the type of resource, there might be other requirements.

Certain types of resources in your tenancy are designed to be directly reachable from the internet and therefore automatically come with a public IP address. For example: a NAT gateway or a public load balancer. Other types of resources are directly reachable only if you configure them to be. For example: instances in your VCN.

There are two types of public IPs:

  • Ephemeral: Think of it as temporary and existing for the lifetime of the instance.
  • Reserved: Think of it as persistent and existing beyond the lifetime of the instance it's assigned to. You can unassign it and then reassign it to another instance whenever you like. Exception: reserved public IPs on public load balancers.

You can perform the public IP address management tasks:

See Public IP Addresses in the Oracle Cloud Infrastructure documentation for more information on this topic.

Ephemeral Public IP Addresses

The following sections address using ephemeral IP addresses:

Assigning an Ephemeral Public IP when Launching an Instance

When you launch an instance into a public subnet, there is an Assign a Public IPv4 Address check box on the Create Compute Instance dialog box. By default, the check box is selected, which means the instance gets an ephemeral public IP. If you do not want an ephemeral public IP assigned, perform one of the following:

  • Deselect Assign a Public IPv4 Address.

  • Delete the ephemeral public IP after instance launch.

Assigning an Ephemeral Public IP when Creating a Secondary VNIC

When you add a secondary VNIC to an instance, you choose whether the primary private IP on the new VNIC gets an ephemeral public IP. This choice is available only if the secondary VNIC is in a public subnet.

In the Create VNIC dialog box, there is an Assign a public IPv4 address check box. By default, the check box is not selected, which means the secondary VNIC does not get an ephemeral public IP. You must select the check box.

Assigning an Ephemeral Public IP to an Existing Private IP

The primary private IP must not have a reserved or ephemeral public IP already assigned to it. If it does, first delete the ephemeral public IP, or unassign the reserved public IP.

  1. Open the navigation menu and click Compute. Click Instances under Compute. The instances are listed in tabular form.

  2. Click the instance with the attached VNIC you need. The instance's Details page appears.

  3. Click Attached VNICs under Resources. The primary VNIC and any secondary VNICs attached to the instance are listed in tabular form.

  4. Click the VNIC with the IP address that you need. The VNIC's Details page appears.

  5. Click IP Addresses under Resources. The VNIC's primary private IP and any secondary private IPs are listed in tabular form.

  6. Click the Actions menu (Actions Menu) for the VNIC's primary private IP, then select Edit. The Edit Private IP Address dialog box appears.

  7. Select the Ephemeral Public IP option under Public IP Type. The Ephemeral Public IP Address box appears.

  8. (optional) Enter an name for the public IP.

  9. Click Update.

Deleting an Ephemeral Public IP from an Instance

  1. Open the navigation menu and click Compute. Click Instances under Compute. The instances are listed in tabular form.

  2. Click the instance with the attached VNIC you need. The instance's Details page appears.

  3. Click Attached VNICs under Resources. The primary VNIC and any secondary VNICs attached to the instance are listed in tabular form.

  4. Click the VNIC with the IP address that you need. The VNIC's Details page appears.

  5. Click IP Addresses under Resources. The VNIC's primary private IP and any secondary private IPs are listed in tabular form.

  6. Click the Actions menu (Actions Menu) for the VNIC's primary private IP, then select Edit. The Edit Private IP Address dialog box appears.

  7. Select the No Public IP option under Public IP Type.

  8. Click Update.

Renaming an Ephemeral Public IP

  1. Open the navigation menu and click Compute. Click Instances under Compute. The instances are listed in tabular form.

  2. Click the instance with the attached VNIC you need. The instance's Details page appears.

  3. Click Attached VNICs under Resources. The primary VNIC and any secondary VNICs attached to the instance are listed in tabular form.

  4. Click the VNIC with the IP address that you need. The VNIC's Details page appears.

  5. Click IP Addresses under Resources. The VNIC's primary private IP and any secondary private IPs are listed in tabular form.

  6. Click the Actions menu (Actions Menu) for the VNIC's primary private IP, then select Edit. The Edit Private IP Address dialog box appears.

  7. Update the ephemeral public IP's name in the Ephemeral Public IP Address box.

  8. Click Update.