Cannot Enable DNS Support & Hostnames for VPC

Question

I created multiple VPCs in us-east-1, and in us-east-2, but AWS is not allowing me to enable EnableDnsSupport and EnableDnsHostnames.

I have tried modifying attributes via CLI, manually in AWS Console, and switching regions.
    Running describe-vpcs shows null for both values.
    This is blocking private DNS resolution for my VPC Endpoint.
    AWS should enable these settings by default.

How can I fix this, or is this an AWS backend issue?

Note: I am a student, and this is a lab I am trying to run based on my given instructions, but I can't even dig into it because my resources won't provision properly. I will delete this entire resource afterward; this is not something that will be used under real load/production.

Riku_Kobayashi · Answer

Hello.

Are any errors occurring when changing settings?  
Also, can I check the VPC DNS settings using the "describe-vpc-attribute" command?  
"EnableDnsSupport" included in the response is basically never null, so there may be a problem or a restriction on the AWS account side.  
https://awscli.amazonaws.com/v2/documentation/api/latest/reference/ec2/describe-vpc-attribute.html  
```
aws ec2 describe-vpc-attribute --vpc-id vpc-a01106c2 --attribute enableDnsSupport
aws ec2 describe-vpc-attribute --vpc-id vpc-a01106c2 --attribute enableDnsHostnames
```

Joshua · Answer

Here is the output it keeps giving me from these commands, in us-east-1, us-east-2, and us-west-2:

~ $ aws ec2 describe-vpcs --vpc-ids vpc-0c1b3c572741953fd --region us-west-2 --query "Vpcs[0].{DnsSupport:EnableDnsSupport, DnsHostnames:EnableDnsHostnames}"

~ $ aws ec2 modify-vpc-attribute --vpc-id vpc-0c1b3c572741953fd --region us-west-2 --enable-dns-support

~ $ aws ec2 modify-vpc-attribute --vpc-id vpc-0c1b3c572741953fd --region us-west-2 --enable-dns-hostnames

~ $ aws ec2 describe-vpcs --vpc-ids vpc-0c1b3c572741953fd --region us-west-2 --query "Vpcs[0].{DnsSupport:EnableDnsSupport, DnsHostnames:EnableDnsHostnames}"

{
    "DnsSupport": null,
    "DnsHostnames": null
}
~ $

I run debug commands, and nothing seems out of the ordinary regarding errors that I can see.

aws ec2 modify-vpc-attribute --vpc-id vpc-0c1b3c572741953fd --region us-west-2 --enable-dns-support --debug

aws ec2 modify-vpc-attribute --vpc-id vpc-0c1b3c572741953fd --region us-west-2 --enable-dns-hostnames --debug

Here is the "describe-vpc-attribute" output:

~ $ aws ec2 describe-vpc-attribute --vpc-id vpc-0c1b3c572741953fd --attribute enableDnsSupport --region us-west-2
{
    "EnableDnsSupport": {
        "Value": true
    },
    "VpcId": "vpc-0c1b3c572741953fd"
}
~ $

But I am still getting the null output mentioned above. I wonder if this has to do with an account-level restriction (basic support account) that is preventing modifications. But if that's the case I don't know why or how to get around that.

Cannot Enable DNS Support & Hostnames for VPC

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