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What's Changed

Learn about what changed in this release for PTX Series routers.

Class of Service (CoS)

  • For PTX Series devices running Junos OS Evolved, software priority medium-low maps to hardware priority medium for normal scheduling mode and low for strict priority scheduling mode.

Juniper Extension Toolkit (JET)

  • Python 3 is the default and only Python version for executing Juniper Extension Toolkit Python scripts (ACX Series, PTX Series, and QFX Series)—Junos OS Evolved supports only Python 3 for executing Juniper Extension Toolkit (JET) scripts written in Python. Python 2.7 is no longer supported for executing JET scripts, and we've deprecated the language python statement at the [edit system scripts] hierarchy level.

    [See Understanding Python Automation Scripts for Junos Devices.]

Junos OS API and Scripting


  • Starting with Junos Evolved Release 21.4R3 a CSPF LSP uses a new instance ID when attempting to re-signal a down LSP.

User Interface and Configuration

  • Support for temperature sensor (PTX10001-36MR)—We support the temperature sensor statement at the edit chassis cb hierarchy level. You can use the temperature sensor statement to increase the fan speed and customize the temperature threshold. We recommend certain values for ZR and ZR-M modules to work which helps the temperature to remain within the thresholds.

    [See temperature-sensor.]