Solve Amazon SSH_exchange_identification: Read: Connection Reset by Peer Error When Changing Permissions

Solve Amazon SSH_exchange_identification: Read: Connection Reset by Peer Error When Changing Permissions

As a data scientist or software engineer, you’ve probably encountered the error ssh_exchange_identification: read: Connection reset by peer when working with Amazon Web Services (AWS) and trying to change permissions. This error typically occurs when trying to connect to an instance via SSH, and it can be quite a headache if you’re not sure how to troubleshoot it.

In this post, we’ll explain what this error means, and then provide a step-by-step guide on how to resolve it.

Understanding the Error

The ssh_exchange_identification: read: Connection reset by peer error is a common SSH error that can occur when connecting to a remote server. It’s often caused by a server-side issue, such as a misconfiguration of the SSH daemon (sshd) or a problem with the server’s firewall settings.

If you’re encountering this error when changing permissions in AWS, it’s likely because the instance is not properly configured to handle SSH connections, or because the instance’s security group does not allow SSH connections.

How to Solve the Error

Here’s a step-by-step guide to resolving this error:

1. Check the Instance’s Security Group

The instance’s security group should allow incoming SSH connections. For this, you’ll need to:

• Go to the AWS EC2 console.
• Select the instance you’re trying to connect to.
• Check the ‘Security groups’ tab.
• Ensure there’s a rule that allows incoming SSH connections (port 22) from your IP address.

If there isn’t, add a new rule:

- Click on 'Edit inbound rules'.
- Click on 'Add rule'.
- For 'Type', select 'SSH'.
- For 'Source', select 'My IP'.
- Click 'Save rules'.

2. Check the SSHD Configuration

If the security group is correctly configured, the next step is to check the SSHD configuration on the instance. For this, you’ll need to connect to the instance using an alternative method, such as the AWS Systems Manager Session Manager.

Once connected, open the SSHD configuration file with:

sudo nano /etc/ssh/sshd_config

Check that the following lines are present and uncommented:

PermitRootLogin prohibit-password
PasswordAuthentication no
UsePAM yes

Save and close the file, then restart the SSHD service with:

sudo service sshd restart

3. Check the Instance’s File Permissions

Finally, check that the permissions of the instance’s SSH files are correct:

ls -la /home/ec2-user/.ssh

The permissions should be as follows:

• The .ssh directory should be 700 (drwx).
• The authorized_keys file should be 600 (-rw-------).

If they’re not, change them with:

chmod 700 /home/ec2-user/.ssh
chmod 600 /home/ec2-user/.ssh/authorized_keys

Then, try connecting to the instance again.

Conclusion

The ssh_exchange_identification: read: Connection reset by peer error can be frustrating, but it’s usually easy to solve by checking and adjusting the instance’s security group, SSHD configuration, and file permissions. By following the steps above, you should be able to successfully connect to your AWS instance via SSH, even when changing permissions.

If you found this guide helpful, or if you have any additional questions or comments, feel free to leave a comment below. Also, don’t forget to share this post with others who might find it useful!

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