title: ASP.NET Core 2.1 Invalid Request Line Issue
body: <p>Our Linux Docker ASP.NET Core container server logs are getting filled by the following 'Informational' log entries since we've updated from .NET Core 2.0 to .NET Core 2.1 (SDK 2.1.302):</p>
  
  <pre><code>INFO|Microsoft.AspNetCore.Server.Kestrel|Connection id "0HLFG42JUAORG" bad request 
  data: "Invalid request line: 
  'CNXN\x00\x00\x00\x01\x00\x00\x04\x00\x1B\x00\x00\x00M\x0A'" 
  Microsoft.AspNetCore.Server.Kestrel.Core.BadHttpRequestException: Invalid 
  request line: 'CNXN\x00\x00\x00\x01\x00\x00\x04\x00\x1B\x00\x00\x00M\x0A'
  
  INFO|Microsoft.AspNetCore.Server.Kestrel|Connection id "0HLFG42JUAORH" bad request 
  data: "Invalid request line: 
  'CNXN\x00\x00\x00\x01\x00\x00\x04\x00\x1B\x00\x00\x00M\x0A'" 
  Microsoft.AspNetCore.Server.Kestrel.Core.BadHttpRequestException: Invalid 
  request line: 'CNXN\x00\x00\x00\x01\x00\x00\x04\x00\x1B\x00\x00\x00M\x0A'
  </code></pre>
  
  <p>The connection ID is incrementing by 1 alpha/digit every second or so. The hex doesn't seem translate to anything meaningful (<code>NUL NUL NUL SOH NUL NUL EOT NUL ESC NUL NUL LF</code>).</p>
  
  <p>Things we've ruled out:</p>
  
  <ul>
  <li>It's not originating from WAN/LAN (disabled network access to the
  containers and the entries are still being generated). </li>
  <li>It doesn't occur in our development environment (windows w/ Visual Studio)</li>
  <li>Redeploying the docker container doesn't fix the issue.</li>
  <li>We don't believe it to be an SSL issue since kestrel is configured for http only. We can access the app and it's websockets (SignalR) over https and wss</li>
  </ul>