When an elastic network interface (ENI) no longer needs one or more secondary private IP addresses, you can unassign the addresses from the ENI.

Prerequisites

The following requirements are met:
  • One or more secondary private IP address are assigned to the ENI from which you want to unassign secondary private IP addresses.
  • The ENI is in the Available (Available) or Bound (InUse) state.
  • When you unassign secondary private IP addresses from a primary ENI, the Elastic Compute Service (ECS) instance to which the primary ENI is attached is in the Running (Running) or Stopped (Stopped) state.

Unassign secondary private IP addresses on the Network Interfaces page

  1. Log on to the ECS console.
  2. In the left-side navigation pane, choose Network & Security > ENIs.
  3. In the top navigation bar, select a region.
  4. On the Network Interfaces page, find the ENI from which you want to unassign secondary private IP addresses and click Manage Secondary Private IP Address in the Actions column.
  5. In the Manage Secondary Private IP Address dialog box, find the secondary private IP addresses that you want to unassign and click Unassign for each of the IP addresses.
  6. Click OK.

Unassign secondary private IP addresses on the Instances page

When you unassign secondary private IP addresses for an instance on the Instances page of the ECS console, the secondary private IP addresses are unassigned from the primary ENI of the instance.

  1. Log on to the ECS console.
  2. In the left-side navigation pane, choose Instances & Images > Instances.
  3. In the top navigation bar, select a region.
  4. On the Instances page, find the instance for which you want to unassign secondary private IP addresses and choose More > Network and Security Group > Manage Secondary Private IP Address in the Actions column.
  5. In the Manage Secondary Private IP Address dialog box, find the secondary private IP addresses that you want to unassign and click Unassign for each of the IP addresses.
  6. Click OK.

Unassign secondary private IP addresses on the Security Groups page

  1. Log on to the ECS console.
  2. In the left-side navigation pane, choose Network & Security > Security Groups.
  3. In the top navigation bar, select a region.
  4. Find the security group to which the ENI that you want to manage belongs and click Manage ENIs in the Actions column.
  5. On the ENIs in Security Group page, find the ENI from which you want to unassign secondary private IP addresses and click Manage Secondary Private IP Address in the Actions column.
  6. In the Manage Secondary Private IP Address dialog box, find the secondary private IP addresses that you want to unassign and click Unassign for each of the IP addresses.
  7. Click OK.