[JENKINS-15387] tcpSlaveAgentListener/ in invalid: - 1 null" when trying to create slave connection via Java Web Start

Jenkins version 1.461.

I try to create Slave Jenkins on Windows 7 machine (master is on Linux) using Java Web start.

1. I connect master Jenkins via browser on Windows machine

2. I go to "Management Nodes"

3. I select the slave node and configuration.

4. When I "launch agent from browser on slave" I get error message

"java.lang.Exception: http://:8080/tcpSlaveAgentListener/ is invalid: -1 null at hudson.remoting.Engine.run(engine.java:179)".

See the attachments.

There is a firewall between slave and master and I have set on master "system configuration" in "Enable security" TCP port for JNLP slave agent: fixed: 20999. This port is open in the firewall.

What could be wrong?

I reboot Master Jenkins but same error message.

I deleted slave node and created a new -> same message

At the very fist time needed files was copied from master to slave into C:\Jenkins folder, but now it doesn't copy nothing.

"Enable security" is unchecked every time, but when I check it I can see setting for the fixed port.

Let me know what more information you need?

---
Originally reported by pentti_aaltonen, imported from: tcpSlaveAgentListener/ in invalid: - 1 null" when trying to create slave connection via Java Web Start

• assignee: kohsuke
  
• status: Open
  
• priority: Major
  
• component(s): slave-setup-plugin
  
• resolution: Unresolved
  
• votes: 0
  
• watchers: 2
  
• imported: 20251216-225446
  

Raw content of original issue

Jenkins version 1.461.


I try to create Slave Jenkins on Windows 7 machine (master is on Linux) using Java Web start.

1. I connect master Jenkins via browser on Windows machine

2. I go to "Management Nodes"

3. I select the slave node and configuration.

4. When I "launch agent from browser on slave" I get error message


 "java.lang.Exception: http://<master jenkins machine>:8080/tcpSlaveAgentListener/ is invalid: -1 null at hudson.remoting.Engine.run(engine.java:179)".


See the attachments.


There is a firewall between slave and master and I have set on master "system configuration" in "Enable security" TCP port for JNLP slave agent: fixed: 20999. This port is open in the firewall.


What could be wrong?

I reboot Master Jenkins but same error message.

I deleted slave node and created a new -> same message

At the very fist time needed files was copied from master to slave into C:\Jenkins folder, but now it doesn't copy nothing.


"Enable security" is unchecked every time, but when I check it I can see setting for the fixed port.


Let me know what more information you need?

environment

```
Master Jenkins on Linux

Slave node on Windows 7
```

3 attachments

- [Jenkins_enbale_security.pdf](https://issues.jenkins.io/secure/attachment/22615/Jenkins_enbale_security.pdf)
- [Jenkins_tcpSlaveAgentListener.pdf](https://issues.jenkins.io/secure/attachment/22613/Jenkins_tcpSlaveAgentListener.pdf)
- [slave_jenkins_config.pdf](https://issues.jenkins.io/secure/attachment/22614/slave_jenkins_config.pdf)