title: Jenkins - Can't download upgrades / plugins - Proxy is already set - Able to reach .hpi via http fine in IE
body: <p>I got the Windows Native .zip from Jenkins site and installed Jenkins on my machine (Win 7) as Windows service.</p>
  
  <p>The nice dashboard is up and now I want to download some plugins / even upgrade the version (First) as I got the .zip few weeks back.</p>
  
  <p>When I tried to upgrade / download the plugins (under Manage Jenkins), I'm getting the following error messages, any idea what I could be missing. </p>
  
  <p>Under Plugin's ADVANCE tab, I have provided the proxy server and port. Another point I noticed that when I'm downloading a plugin (and it fails) showing the link to the plugin .hpi file, if I use that "http ://../../.hpi" in Internet Explorer, it pops up fine (telling me to open/save etc) so in one sense, I'm able to reach the .hpi file directly. I can download the .hpi file manually and put it under the Jenkins installation/..respective/../../folder and restart Jenkins service everytime I install a new/replace an existing .hpi, but that I dont want to do that.</p>
  
  <p><strong>Installing Plugins/Upgrades</strong></p>
  
  <pre><code>Preparation 
  
      Checking internet connectivity
      Checking update center connectivity
      java.net.ConnectException: Connection refused: connect at java.net.PlainSocketImpl.socketConnect(Native Method) at java.net.PlainSocketImpl.doConnect(Unknown Source) at java.net.PlainSocketImpl.connectToAddress(Unknown Source) at java.net.PlainSocketImpl.connect(Unknown Source) at java.net.SocksSocketImpl.connect(Unknown Source) at java.net.Socket.connect(Unknown Source) at java.net.Socket.connect(Unknown Source) at sun.net.NetworkClient.doConnect(Unknown Source) at sun.net.www.http.HttpClient.openServer(Unknown Source) at sun.net.www.http.HttpClient.openServer(Unknown Source) at sun.net.www.http.HttpClient.(Unknown Source) at sun.net.www.http.HttpClient.New(Unknown Source) at sun.net.www.http.HttpClient.New(Unknown Source) at sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(Unknown Source) at sun.net.www.protocol.http.HttpURLConnection.plainConnect(Unknown Source) at sun.net.www.protocol.http.HttpURLConnection.connect(Unknown Source) at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source) at hudson.model.UpdateCenter$UpdateCenterConfiguration.testConnection(UpdateCenter.java:860) at hudson.model.UpdateCenter$UpdateCenterConfiguration.checkUpdateCenter(UpdateCenter.java:709) at hudson.model.UpdateCenter$ConnectionCheckJob.run(UpdateCenter.java:1030) at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source) at java.util.concurrent.FutureTask.run(Unknown Source) at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source) at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) at java.lang.Thread.run(Unknown Source) 
  
  jenkins.war 
  Failure -
  
  hudson.util.IOException2: Failed to download from http://updates.jenkins-ci.org/download/war/1.508/jenkins.war
      at hudson.model.UpdateCenter$UpdateCenterConfiguration.download(UpdateCenter.java:782)
      at hudson.model.UpdateCenter$DownloadJob._run(UpdateCenter.java:1123)
      at hudson.model.UpdateCenter$DownloadJob.run(UpdateCenter.java:1101)
      at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
      at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)
      at java.util.concurrent.FutureTask.run(Unknown Source)
      at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
      at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
      at java.lang.Thread.run(Unknown Source)
  Caused by: java.net.ConnectException: Connection refused: connect
      at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
      at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
      at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
      at java.lang.reflect.Constructor.newInstance(Unknown Source)
      at sun.net.www.protocol.http.HttpURLConnection$6.run(Unknown Source)
      at java.security.AccessController.doPrivileged(Native Method)
      at sun.net.www.protocol.http.HttpURLConnection.getChainedException(Unknown Source)
      at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
      at hudson.model.UpdateCenter$UpdateCenterConfiguration.download(UpdateCenter.java:752)
      ... 8 more
  Caused by: java.net.ConnectException: Connection refused: connect
      at java.net.PlainSocketImpl.socketConnect(Native Method)
      at java.net.PlainSocketImpl.doConnect(Unknown Source)
      at java.net.PlainSocketImpl.connectToAddress(Unknown Source)
      at java.net.PlainSocketImpl.connect(Unknown Source)
      at java.net.SocksSocketImpl.connect(Unknown Source)
      at java.net.Socket.connect(Unknown Source)
      at java.net.Socket.connect(Unknown Source)
      at sun.net.NetworkClient.doConnect(Unknown Source)
      at sun.net.www.http.HttpClient.openServer(Unknown Source)
      at sun.net.www.http.HttpClient.openServer(Unknown Source)
      at sun.net.www.http.HttpClient.&lt;init&gt;(Unknown Source)
      at sun.net.www.http.HttpClient.New(Unknown Source)
      at sun.net.www.http.HttpClient.New(Unknown Source)
      at sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(Unknown Source)
      at sun.net.www.protocol.http.HttpURLConnection.plainConnect(Unknown Source)
      at sun.net.www.protocol.http.HttpURLConnection.connect(Unknown Source)
      at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
      at sun.net.www.protocol.http.HttpURLConnection.getHeaderField(Unknown Source)
      at java.net.URLConnection.getHeaderFieldInt(Unknown Source)
      at java.net.URLConnection.getContentLength(Unknown Source)
      at hudson.model.UpdateCenter$UpdateCenterConfiguration.download(UpdateCenter.java:751)
      ... 8 more
  
  Preparation 
  
      Checking internet connectivity
      Checking update center connectivity
      java.io.IOException: Server returned HTTP response code: 403 for URL: http://updates.jenkins-ci.org/update-center.json?uctest at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source) at hudson.model.UpdateCenter$UpdateCenterConfiguration.testConnection(UpdateCenter.java:860) at hudson.model.UpdateCenter$UpdateCenterConfiguration.checkUpdateCenter(UpdateCenter.java:709) at hudson.model.UpdateCenter$ConnectionCheckJob.run(UpdateCenter.java:1030) at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source) at java.util.concurrent.FutureTask.run(Unknown Source) at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source) at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) at java.lang.Thread.run(Unknown Source) 
  
  Timestamper 
  Failure -
  
  hudson.util.IOException2: Failed to download from http://updates.jenkins-ci.org/download/plugins/timestamper/1.5.3/timestamper.hpi
      at hudson.model.UpdateCenter$UpdateCenterConfiguration.download(UpdateCenter.java:782)
      at hudson.model.UpdateCenter$DownloadJob._run(UpdateCenter.java:1123)
      at hudson.model.UpdateCenter$InstallationJob._run(UpdateCenter.java:1285)
      at hudson.model.UpdateCenter$DownloadJob.run(UpdateCenter.java:1101)
      at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
      at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)
      at java.util.concurrent.FutureTask.run(Unknown Source)
      at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
      at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
      at java.lang.Thread.run(Unknown Source)
  Caused by: java.io.IOException: Server returned HTTP response code: 403 for URL: http://updates.jenkins-ci.org/download/plugins/timestamper/1.5.3/timestamper.hpi
      at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
      at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
      at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
      at java.lang.reflect.Constructor.newInstance(Unknown Source)
      at sun.net.www.protocol.http.HttpURLConnection$6.run(Unknown Source)
      at java.security.AccessController.doPrivileged(Native Method)
      at sun.net.www.protocol.http.HttpURLConnection.getChainedException(Unknown Source)
      at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
      at hudson.model.UpdateCenter$UpdateCenterConfiguration.download(UpdateCenter.java:752)
      ... 9 more
  Caused by: java.io.IOException: Server returned HTTP response code: 403 for URL: http://updates.jenkins-ci.org/download/plugins/timestamper/1.5.3/timestamper.hpi
      at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
      at sun.net.www.protocol.http.HttpURLConnection.getHeaderField(Unknown Source)
      at java.net.URLConnection.getHeaderFieldInt(Unknown Source)
      at java.net.URLConnection.getContentLength(Unknown Source)
      at hudson.model.UpdateCenter$UpdateCenterConfiguration.download(UpdateCenter.java:751)
      ... 9 more
  </code></pre>