less efficient HTTP transport. There are a number of common problems that may be experienced when running the CLI client. Check that the HTTP or TCP port is opened if you are using a firewall on your server. You can configure its value in Jenkins configuration. By default it is set to use a random port. Common Problems with the Remoting-based client Operation timed out Go to  Manage Jenkins  >  Configure Global Security  and choose "Fixed" or "Random" under  TCP port for JNLP agents . % java -jar jenkins-cli.jar -s JENKINS_URL help Exception in thread "main" java.net.ConnectException: Operation timed out at java.net.PlainSocketImpl.socketConnect(Native Method) at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:351) at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:213) at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:200) at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:432) at java.net.Socket.connect(Socket.java:529) at java.net.Socket.connect(Socket.java:478) at java.net.Socket.<init>(Socket.java:375) at java.net.Socket.<init>(Socket.java:189) at hudson.cli.CLI.<init>(CLI.java:97) at hudson.cli.CLI.<init>(CLI.java:82) at hudson.cli.CLI._main(CLI.java:250) at hudson.cli.CLI.main(CLI.java:199) 174 No X-Jenkins-CLI2-Port