Allow Address Pairs — Overview
What is Allow Address Pairs?
Allow Address Pairs is a feature that allows a Network Interface Card (NIC) on an Instance to send and receive network traffic for IP addresses or CIDR ranges beyond the primary IP assigned to that NIC.
By default, the virtual networking layer only permits traffic through a NIC when the source address exactly matches the NIC's primary IP. Allow Address Pairs relaxes this restriction by declaring additional (IP/CIDR, MAC) pairs that are accepted, enabling advanced architectural patterns such as:
- Virtual IP (VIP): A shared IP address that can be transferred between multiple Instances when a primary Instance fails.
- High Availability (HA): An active-standby cluster that uses a floating IP which migrates to the standby node when the active node goes down.
- Load Balancer or Router VM: An Instance acting as a load balancer or routing device that needs to handle packets destined for multiple different IP addresses.
- Zero-downtime service migration: Shifting traffic from an old Instance to a new one during an upgrade without changing the service IP address.
Scope
Important note: Allow Address Pairs is only available on General VPC. This feature is not supported on Specific VPC.
The feature operates at the NIC level — each Allow Address Pair record is attached to a specific NIC on a specific Instance within the VPC.
What can users do?
| Action | Description |
|---|---|
| View list | View all address pairs that have been permitted within the VPC |
| Create | Add an (IP/CIDR, optional MAC) pair to an Instance's NIC |
| Delete | Remove an address pair that is no longer needed |
Navigation
Access the feature using the following path (within a General VPC context):
VPC → Network → Allow Address Pairs
The list screen displays the following columns:
| Column | Content |
|---|---|
| Instance | Name of the Instance that owns the NIC |
| Network interface card | The NIC to which the address pair is attached |
| IP or CIDR address | The IP address or network range that is permitted |
| MAC address | The permitted MAC address (if specified) |