<p>I created a jenkins master in my OKE cluster (a single node cluster). I wanted to try using Jenkins kubernetes plugin and connect jnlp-slaves.
<a href="https://i.stack.imgur.com/W3fSW.png" rel="nofollow noreferrer">Following are my kuberenetes cloud configurations.</a></p>
<p><a href="https://i.stack.imgur.com/ZY17I.png" rel="nofollow noreferrer">Jenkins tunnel and URL info</a></p>
<p>Jenkins version that Im using is Jenkins 2.319.3. When I start the build, a pod is creating in my cluster and gives an error.</p>
<p>Following is the log of the created pod.</p>
<pre><code>Mar 17, 2022 5:49:10 AM hudson.remoting.jnlp.Main createEngine
INFO: Setting up agent: kube-agent-s8tw6
Mar 17, 2022 5:49:10 AM hudson.remoting.jnlp.Main$CuiListener &lt;init&gt;
INFO: Jenkins agent is running in headless mode.
Mar 17, 2022 5:49:10 AM hudson.remoting.Engine startEngine
INFO: Using Remoting version: 4.11.2
Mar 17, 2022 5:49:10 AM org.jenkinsci.remoting.engine.WorkDirManager initializeWorkDir
INFO: Using /home/jenkins/agent/remoting as a remoting work directory
Mar 17, 2022 5:49:10 AM org.jenkinsci.remoting.engine.WorkDirManager setupLogging
INFO: Both error and output logs will be printed to /home/jenkins/agent/remoting
Mar 17, 2022 5:49:10 AM hudson.remoting.jnlp.Main$CuiListener status
INFO: Locating server among [http://138.2.75.190:30000/]
Mar 17, 2022 5:49:10 AM org.jenkinsci.remoting.engine.JnlpAgentEndpointResolver resolve
INFO: Remoting server accepts the following protocols: [JNLP4-connect, Ping]
Mar 17, 2022 5:49:10 AM org.jenkinsci.remoting.engine.JnlpAgentEndpointResolver resolve
INFO: Remoting TCP connection tunneling is enabled. Skipping the TCP Agent Listener Port availability check
Mar 17, 2022 5:49:10 AM hudson.remoting.jnlp.Main$CuiListener status
INFO: Agent discovery successful
  Agent address: http://138.2.75.190
  Agent port:    50000
  Identity:      5b:f2:ef:be:d1:98:05:91:83:3d:a5:61:b6:1b:93:e5
Mar 17, 2022 5:49:10 AM hudson.remoting.jnlp.Main$CuiListener status
INFO: Handshaking
Mar 17, 2022 5:49:10 AM hudson.remoting.jnlp.Main$CuiListener status
INFO: Connecting to http://138.2.75.190:50000
Mar 17, 2022 5:49:10 AM hudson.remoting.jnlp.Main$CuiListener error
SEVERE: null
java.nio.channels.UnresolvedAddressException
    at java.base/sun.nio.ch.Net.checkAddress(Unknown Source)
    at java.base/sun.nio.ch.SocketChannelImpl.connect(Unknown Source)
    at java.base/java.nio.channels.SocketChannel.open(Unknown Source)
    at org.jenkinsci.remoting.engine.JnlpAgentEndpoint.open(JnlpAgentEndpoint.java:206)
    at hudson.remoting.Engine.connectTcp(Engine.java:880)
    at hudson.remoting.Engine.innerRun(Engine.java:757)
    at hudson.remoting.Engine.run(Engine.java:540)
</code></pre>
<p>I checked the ports and I disabled firewall in my node. Im still getting the error. Can someone help me to solve this?</p>

IamM96
<p>I faced the same error and solved.</p>
<p>In error logs we can see you defined tunnel address as 'http://138.2.75.190:50000'</p>
<pre class="lang-bash prettyprint-override"><code>...
INFO: Connecting to http://138.2.75.190:50000
...
</code></pre>
<p>You added 'http://' prefix to Jenkins tunnel address and this is causing error. Expected address must be 'host:port' format, not 'protocol://host:port'</p>
<p>So for fix this error just remove 'http://' prefix from tunnel address. For your case; it should be '138.2.75.190:50000'</p>
<p>Change it in Jenkins Kubernetes configuration page.</p>
