Got Unsupported RunInstances error.. but I didn't specify an Availability Zone

Question

I got this error on CLI:

`An error occurred (Unsupported) when calling the RunInstances operation: Your requested instance type (c5.2xlarge) is not supported in your requested Availability Zone (us-east-1e). Please retry your request by not specifying an Availability Zone or choosing us-east-1a, us-east-1b, us-east-1c, us-east-1d, us-east-1f.`

This looks very reasonable. But how do I do not specify an Availability Zone? The command I ran which gave the above error just used `us-east-1`, not `us-east-1e`. Where's it getting us-east-1e? I did not specify that.

Here's the full command I ran:
`aws --output json ec2 run-instances --region=us-east-1 --client-token=some-client-token --image-id=ami-someimage-id --instance-type=c5.2xlarge --associate-public-ip-address --subnet-id=subnet-id --placement=GroupName=my-group-name`

Associated support article also does not give an example of how to not specify an Availability Zone:
https://aws.amazon.com/premiumsupport/knowledge-center/ec2-instance-type-not-supported-az-error/

Accepted Answer

By specifying a subnet you are choosing and availability zone. When a subnet is created you must specify the AZ that it is assigned to; so launching an instance in a subnet chooses that AZ.

Answer

Hi Howellz,
I think the error message is clear, and you ran  specifying **us-east-1**.
```
aws --output json ec2 run-instances --region=us-east-1 --client-token=some-client-token --image-id=ami-someimage-id --instance-type=c5.2xlarge --associate-public-ip-address --subnet-id=subnet-id --placement=GroupName=my-group-name
```

Apparently you need to replace the region with one of the provided options: **us-east-1a, us-east-1b, us-east-1c, us-east-1d, us-east-1f.**

Can you try using one of those and see if it works?

Got Unsupported RunInstances error.. but I didn't specify an Availability Zone

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