Table Of Contents


User Guide

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[ aws . elb ]



Adds the specified instances to the specified load balancer.

The instance must be a running instance in the same network as the load balancer (EC2-Classic or the same VPC). If you have EC2-Classic instances and a load balancer in a VPC with ClassicLink enabled, you can link the EC2-Classic instances to that VPC and then register the linked EC2-Classic instances with the load balancer in the VPC.

Note that RegisterInstanceWithLoadBalancer completes when the request has been registered. Instance registration takes a little time to complete. To check the state of the registered instances, use describe-load-balancers or describe-instance-health .

After the instance is registered, it starts receiving traffic and requests from the load balancer. Any instance that is not in one of the Availability Zones registered for the load balancer is moved to the OutOfService state. If an Availability Zone is added to the load balancer later, any instances registered with the load balancer move to the InService state.

To deregister instances from a load balancer, use deregister-instances-from-load-balancer .

For more information, see Register or De-Register EC2 instances in the Classic Load Balancer Guide .

See also: AWS API Documentation


--load-balancer-name <value>
--instances <value>
[--cli-input-json <value>]
[--generate-cli-skeleton <value>]


--load-balancer-name (string)

The name of the load balancer.

--instances (list)

The IDs of the instances.

Shorthand Syntax:

--instances InstanceId1 InstanceId2 InstanceId3

JSON Syntax:

    "InstanceId": "string"

--cli-input-json (string) Performs service operation based on the JSON string provided. The JSON string follows the format provided by --generate-cli-skeleton. If other arguments are provided on the command line, the CLI values will override the JSON-provided values.

--generate-cli-skeleton (string) Prints a JSON skeleton to standard output without sending an API request. If provided with no value or the value input, prints a sample input JSON that can be used as an argument for --cli-input-json. If provided with the value output, it validates the command inputs and returns a sample output JSON for that command.


To register instances with a load balancer

This example registers the specified instance with the specified load balancer.


aws elb register-instances-with-load-balancer --load-balancer-name my-load-balancer --instances i-d6f6fae3


   "Instances": [
           "InstanceId": "i-d6f6fae3"
           "InstanceId": "i-207d9717"
           "InstanceId": "i-afefb49b"


Instances -> (list)

The updated list of instances for the load balancer.


The ID of an EC2 instance.

InstanceId -> (string)

The instance ID.