Failover across AWS subnets using overlay IP - Windows

Last published : Jul 07, 2026
InfoScale clusters let you fail over IPs - and thereby, the application configured for HA - between different subnets in the same AZ or in different AZs.
The following information is required:
  • The overlay IP address to be used for failover
  • The device to which the IP should be plumbed
  • The directory in which the AWS CLI is installed; this input is not required if it is provided in the PATH environment variable
AWS does not allow the private IP of one subnet to be failed over to a different subnet. To overcome this limitation, InfoScale Enterprise provides an overlay IP, which is defined at the VPC level, so that it can be used across subnets.
Sample configuration with overlay IP for failover across subnets in the same AZ
The following graphic depicts a sample failover configuration across subnets within the same AZ using an overlay IP:
image
The sample configuration includes the following elements:
  • A virtual private cloud (VPC) is configured in Region A of the AWS cloud.
  • An application is configured for HA using an InfoScale cluster that comprises two nodes, Node 1 and Node 2, which are EC2 instances.
Node 1 exists in Subnet 1 and Node 2 exists in Subnet 2.
  • An overlay IP is configured, which allows the private IP of a node to be failed over from one subnet to another in an AZ as part of the failover or the failback operations.
Sample service group configuration with overlay IP for failover across subnets in the same AZ
The following snippet is a service group configuration from a sample VCS configuration file (main.cf):
group AWSIPGrp (
          SystemList = { WIN-38PNEVJSR2K = 0 , WIN-39PNEVJSR2K = 1  }
          AutoStartList = { WIN-38PNEVJSR2K, WIN-39PNEVJSR2K }
          )

          AWSIP overlay (
                   OverlayIP = "172.16.8.55/32"
                   Device @WIN-38PNEVJSR2K = 12-7F-CE-5B-E2-6E
                   Device@WIN-39PNEVJSR2K = 12-7F-CE-5B-E2-6F
                   RouteTableIds = { rtb-c5272ca3, rtb-fb97ac9d }
                   )
          IP ipres (
                   Address= "172.16.8.55"
                   SubNetMask = "255.255.254.0"
                   MACAddress @WIN-38PNEVJSR2K = "12:7F:CE:5B:E2:6E"
                   MACAddress @WIN-39PNEVJSR2K = "12:7F:CE:5B:E2:6F"
                   )

          NIC nicres (
                   MACAddress @WIN-38PNEVJSR2K = "12:7F:CE:5B:E2:6E"
                   MACAddress @WIN-39PNEVJSR2K = "12:7F:CE:5B:E2:6F"
                   )

ipres requires nicres
overlayip requires ipres
Sample configuration with overlay IP for failover across subnets in different AZs
The following graphic depicts a sample failover configuration across subnets in different AZs using an overlay IP:
image
Sample service group configuration with overlay IP for failover across subnets in different AZs
The following snippet is a service group configuration from a sample VCS configuration file (main.cf):
group AWSIPGrp (
          SystemList = { WIN-38PNEVJSR2K = 0 , WIN-39PNEVJSR2K = 1  }
          AutoStartList = { WIN-38PNEVJSR2K, WIN-39PNEVJSR2K }
          )

          AWSIP overlay (
                   OverlayIP = "172.16.8.55/32"
                   Device @WIN-38PNEVJSR2K = 12-7F-CE-5B-E2-6E
                   Device@WIN-39PNEVJSR2K = 12-7F-CE-5B-E2-6F
                   RouteTableIds = { rtb-c5272ca3, rtb-fb97ac9d }
                   )
          IP ipres (
                   Address = "172.16.8.55"
                   SubNetMask = "255.255.254.0"
                   MACAddress @WIN-38PNEVJSR2K = "12:7F:CE:5B:E2:6E"
                   MACAddress @WIN-39PNEVJSR2K = "12:7F:CE:5B:E2:6F"
                   )

          NIC nicres (
                   MACAddress @WIN-38PNEVJSR2K = "12:7F:CE:5B:E2:6E"
                   MACAddress @WIN-39PNEVJSR2K = "12:7F:CE:5B:E2:6F"
                   )

ipres requires nicres
overlayip requires ipres