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    Virtual Private Cloud:Route target groups

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    Virtual Private Cloud:Route target groups

    Last Updated:Feb 28, 2026

    A route target group enables automatic failover for your routes. Instead of manually redirecting traffic when your primary next hop fails, configure a route target group with active and standby instances in active-standby mode. The system monitors instance health and automatically switches traffic to the healthy instance, reducing your recovery time to under 30 seconds.

    How it works

    A route target group provides automated zone-level disaster recovery through three steps:

    image

    Active-standby configuration

    Configure two instances of the same type in different zones with predefined roles:

    • Active instance: Weight 100. Handles all traffic when healthy.

    • Standby instance: Weight 0. Activated only when the active instance fails.

    Health monitoring

    The system continuously probes both instances to detect failures and switchovers:

    • Failure detection: Three consecutive failed probes mark an instance as Unhealthy and trigger automatic failover.

    • Recovery verification: Three consecutive successful probes mark an instance as Healthy again.

    Automatic and manual switching

    • Automatic failover: When the active instance fails, traffic automatically switches to the standby instance within 30 seconds.

    • Manual failback: After the active recovers, manually switch traffic back during a maintenance window.

    • Automatic failback not supported: The system does not automatically return traffic to the active instance after recovery to avoid frequent failovers caused by network jitters or service disruptions. Manually fail back during off-peak hours.

    Scenario

    Trigger

    Switchover Time

    Failover

    Automatic (triggered by health check)

    < 30s

    Failback

    Manual

    < 10s

    Usage notes

    • Currently, only Gateway Load Balancer (GWLB) endpoints are supported.

    • You must configure one active instance and one standby instance. Both instances must belong to the same virtual private cloud (VPC) and be deployed in different zones to enable cross-zone disaster recovery.

    • You can create up to 10 route target groups in a VPC.

    Configure automatic failover

    Configure the next hop of an IPv4 route entry to a route target group. Traffic is sent to the active instance in the group, and automatically fails over to the standby instance if the active becomes unhealthy.

    • Only IPv4 route entries are supported.

    • A route target group supports the same routing operations as its member instances. For example, if a system route in a gateway route table can use a GWLB endpoints as the next hop, it can also use a route target group that contains that GWLB endpoints.

    Console

    1. Go to the VPC - Route Target Groups page and click Create Target Group.

      • VPC: Select the VPC where your GWLB endpoints reside.

      • Mode: Keep the default Active/Standby Mode.

      • Member Type: Select GWLB Endpoint.

      • Member: Select an active and a standby instance. Ensure they are in different zones.

        After creation, you can modify inactive instances from the target group details page by clicking Modify Member. Active instances cannot be modified.

      • Instance Name, Resource Group and Tags: Use these for data organization.

    2. Configure a route entry to point to the route target group.

      1. Go to the VPC - Route Tables page and click the target route table ID.

      2. On the Custom Route tab, select Add Route Entry.

        • Destination CIDR Block: The destination CIDR for which you want to forward traffic through the active and standby instances.

        • Next Hop Type: Select Route Target Group.

    API

    1. Call CreateRouteTargetGroup to create a route target group.

    2. Call CreateRouteEntry to create a custom route entry. Set NextHopType to RouteTargetGroup.

    Manually perform a switchover

    • Use cases:

      • Manually switch traffic back during a maintenance window.

      • The system does not automatically return traffic to the active instance after recovery to avoid frequent failovers caused by network jitters or service disruptions. Manually fail back during off-peak hours.

    • Limitation: You can only perform a switchover when both instances are healthy.

    Console

    1. Go to the VPC - Route Target Groups page and click the route target group ID.

    2. In the upper-right corner of the page, click Switch Member.

    API

    Call SwitchActiveRouteTarget to perform a switchover for the route target group.

    Billing

    The route target group feature is free of charge.

    You are charged for the target instances, currently only GWLB endpoints, and their backend services. For more information, see PrivateLink billing and GWLB billing rules.

    Before going live

    Before directing production traffic to a route target group, complete these steps:

    Conduct a disaster recovery drill

    Perform a manual switchover during a maintenance window or off-peak hours to verify:

    • The standby instance can successfully handle traffic.

    • Security group rules allow traffic through the standby path.

    • Backend services respond correctly when using the standby instance.

    Assess connection impact

    For stateful applications (such as firewalls with persistent connections or NAT sessions), a switchover breaks existing connections. Plan accordingly:

    • Implement automatic reconnection for your applications.

    • Test the impact of connection resets on your services.