Windows EC2 Instance is unreachable

Question

I have a windows instance running Windows Server 2019 and after stopping and starting the instance, I cannot connect to it SSM or RDP. When I run aws ec2 get-console-output returns the instance id and timestamp only:

{
    "InstanceId": "i-07dd6exxxxxxxxd1",
    "Timestamp": "2022-04-11T18:25:04+00:00"
}

If I try to execute ssm start session, it times out and returns:

Command '['session-manager-plugin', '{"SessionId": "oscars@blank.com-0473707d8049c843c", "TokenValue": "***", "StreamUrl": "wss://ssmmessages.eu-west-1.amazonaws.com/v1/data-channel/oscars@blank.com-0473707d8049c843c?role=publish_subscribe&cell-number=***", "ResponseMetadata": {"RequestId": "f44033cc-12da-4617-81ad-195e17ef2e69", "HTTPStatusCode": 200, "HTTPHeaders": {"server": "Server", "date": "Mon, 11 Apr 2022 18:06:58 GMT", "content-type": "application/x-amz-json-1.1", "content-length": "839", "connection": "keep-alive", "x-amzn-requestid": "f44033cc-12da-4617-81ad-195e17ef2e69"}, "RetryAttempts": 0}}', 'eu-west-1', 'StartSession', 'prod', '{"Target": "i-07dd6exxxxxxxxd1"}', 'https://ssm.eu-west-1.amazonaws.com']' returned non-zero exit status 3221225786.

Starting an RDP session returns a timeout even though Reachability Analyzer states that the instance is reachable via TCP on port 3389 from another instance. Basically the instance has become unreachable and I can only stop and start it in the console.

Answer

It sounds like there is something on the instance that is stopping the networking stack from working correctly. For example, this could happen if the Windows firewall was incorrectly configured.

You can try mounting the C: drive of the instance on another instance and then looking at logs or editing entries in the registry.

If all else fails, please create a support case and get the team to help you troubleshoot.

Windows EC2 Instance is unreachable

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