# Check the health of your Network Load Balancer targets
<a name="check-target-health"></a>

You can check the health status of the targets registered with your target groups. For help with health check failures, see [Troubleshooting: A registered target is not in service](load-balancer-troubleshooting.md#target-not-in-service).

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#### [ Console ]

**To check the health of your targets**

1. Open the Amazon EC2 console at [https://console.aws.amazon.com/ec2/](https://console.aws.amazon.com/ec2/).

1. In the navigation pane, under **Load Balancing**, choose **Target Groups**.

1. Choose the name of the target group to open its details page.

1. The **Details** tab displays the total number of targets, plus the number of targets for each health status.

1. On the **Targets** tab, the **Health status** column indicates the status of each target.

1. If the status of a target is any value other than `Healthy`, the **Health status details** column contains more information.

**To receive email notifications about unhealthy targets**  
Use CloudWatch alarms to trigger a Lambda function to send details about unhealthy targets. For step-by-step instructions, see the following blog post: [Identifying unhealthy targets of your load balancer](https://aws.amazon.com/blogs/networking-and-content-delivery/identifying-unhealthy-targets-of-elastic-load-balancer/).

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#### [ AWS CLI ]

**To check the health of your targets**  
Use the [describe-target-health](https://docs.aws.amazon.com/cli/latest/reference/elbv2/describe-target-health.html) command. This example filters the output to include only targets that are not healthy. For targets that are not healthy, the output includes a reason code.

```
aws elbv2 describe-target-health \
    --target-group-arn target-group-arn \
    --query "TargetHealthDescriptions[?TargetHealth.State!='healthy'].[Target.Id,TargetHealth.State,TargetHealth.Reason]" \
    --output table
```

The following is example output.

```
----------------------------------------------
|            DescribeTargetHealth            |
+--------------+---------+-------------------+
|  172.31.0.57 |  unused |  Target.NotInUse  |
|  172.31.0.50 |  unused |  Target.NotInUse  |
+--------------+---------+-------------------+
```

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## Target states and reason codes
<a name="target-states-reason-codes"></a>

The following list shows the possible reason codes for each target state.

**Target state is healthy**  
A reason code is not provided.

**Target state is initial**  
+  `Elb.RegistrationInProgress` - The target is in the process of being registered with the load balancer.
+  `Elb.InitialHealthChecking` - The load balancer is still sending the target the minimum number of health checks required to determine its health status.

**Target state is unhealthy**  
+ `Target.FailedHealthChecks` - The load balancer received an error while establishing a connection to the target or the target response was malformed.

**Target state is unused**  
+ `Target.NotRegistered` - The target is not registered with the target group.
+ `Target.NotInUse` - The target group is not used by any load balancer or the target is in an Availability Zone that is not enabled for its load balancer.
+ `Target.InvalidState` - The target is in the stopped or terminated state.
+ `Target.IpUnusable` - The target IP address is reserved for use by a load balancer.

**Target state is draining**  
+ `Target.DeregistrationInProgress` - The target is in the process of being deregistered and the deregistration delay period has not expired.

**Target state is unavailable**  
+ `Elb.InternalError` - Target health is unavailable due to an internal error.