Cannot SSH to an EC2 Hosted Ubuntu vpc instance

Question

I am running into a wall trying to SSH using Putty from a Windows device and I get an error:  ****No supported authentication methods available(server sent: publickey)  when I attempt to run the command: ****

ssh -i keyname.pem ubuntu@ec2-xxx.compute-1.amazonaws.com

I get a connection timeout.

I've recreated the key a couple times and continue to get:  access denied (publickey) errors.

Answer

Make sure your key is only readable by you - `chmod 600 keyname.pem`

Try `ssh -vvv -i ...` and see if it gives you any more details.

And this is just a hunch, I'm guessing it's the latest version of Ubuntu you've built your EC2 with; what version is running on the host that you're trying to SSH from?

It's possible the new version has deprecated some old & insecure encryption algorithms, but when attempting the initial key exchange your SSH client is only able to offer up these.

You can try spinning up an EC2 running an older version of Ubuntu and confirm that you can login with the key on this older version. If you can do that then it proves the keys are good.

Cannot SSH to an EC2 Hosted Ubuntu vpc instance

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