I have a scalable load balancer set up right now that was mostly followed from this template:


After adjusting the AWS::AutoScaling::AutoScalingGroup.CreationPolicy.ResourceSignal.Count key to 0 (basically allows for stack to load with no success signals received) I was able to load the stack and I can see all resources available.

I can see the public DNS of the keys being created, but I cannot SSH into the instance.

I have a opened up SSH access to everyone within my instance rules, I can confirm this within the AWS console.

I also configured a route for my VPC as recommended within the official AWS docs: https://aws.amazon.com/premiumsupport/knowledge-center/ec2-linux-ssh-troubleshooting/

I can see the instances exist, but it seems that I am restricting myself access somewhere. However within the AWS EC2 console, the settings seem to look the same as when I am able to SSH into an instance.

Here is my JSON template I'm using where you can view all my settings including my VPC, subnets, Security Groups, etc.: https://gist.github.com/dambrogia/e4cd93a64ae6f3a79d4a58d466f144f8

I am receiving a timeout error from the following command: (my id_rsa key is valid within ec2)

ssh -i ~/.ssh/id_rsa ec2-user@<ec2_instance>

How can I SSH into my instances? Thanks in advance for the help!

  • 2
    Thumbs up for including your actual CFN template! It really helps :)
    – MLu
    Nov 1 '18 at 18:57

The problem is that the CloudFormation template creates a RouteTable with the default route correctly pointing to the IGW, however you don't associate the RouteTable with your subnets.

enter image description here

What you need to do is add these two Route Table Associations to the template:

            "Type" : "AWS::EC2::SubnetRouteTableAssociation",
                "Properties" : {
                    "RouteTableId" : { "Ref": "RouteTable" },
                    "SubnetId" : { "Ref": "Subnet1" }
            "Type" : "AWS::EC2::SubnetRouteTableAssociation",
                "Properties" : {
                    "RouteTableId" : { "Ref": "RouteTable" },
                    "SubnetId" : { "Ref": "Subnet2" }

Then Update the stack ...

enter image description here

And re-check the Route Table

enter image description here

Now you should be able to SSH to the instances:

~ $ ssh
Last login: Thu Nov  1 18:54:54 2018 from ...

       __|  __|_  )
       _|  (     /   Amazon Linux AMI

[ec2-user@ip-10-0-2-229 ~]$ 

Hope that helps :)

  • Thank you so much for the in-depth answer and explanation. It worked like a charm! Nov 1 '18 at 19:35

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