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[ScreenOS] Unable to telnet\SSH to firewall due to the 'Can't create telnet\ssh-cmd:6 task' error on the console



Article ID: KB24374 KB Last Updated: 28 May 2012Version: 1.0
This article describes the issue of being unable to access the firewall via SSH or Telnet. However, console access is working.
Access to the firewall via SSH and Telnet is failing and the following errors are generated on the console:

  • For Telnet: Can't create telnet-cmd:6 task

  • For SSH: Can't create ssh-cmd:140 task
  • This is due to the maximum number of allowed tasks being reached on the device.

  • SSGs can support up to a maximum of 112 tasks (0-111). This limit was applicable for releases below 6.2r5, 6.3r2, and 5.4r16.

  • So, if the above errors are generated, you can check the number of tasks being used by executing the get os task command.

The number of tasks required by ScreenOS was increased with time; however, the number of tasks supported was not increased for SSG platforms. Specifically, the number of tasks required for the TASK AV WORKER was increased. So, as a workaround, the AV license can be removed, which will free up a lot of tasks.

As a permanent fix, the task limit was increased to 144 in SSG devices and the following releases contain the fix:

  • 6.3r2 and above

  • 6.2r5 and above

  • 5.4r16 and above
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