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Junos OS Release Notes for NFX Series


These release notes accompany Junos OS Release 17.4R3 for the NFX Series. They describe new and changed features, limitations, and known and resolved problems in the hardware and software.

You can also find these release notes on the Juniper Networks Junos OS Documentation webpage, located at

New and Changed Features

This section describes the new features and enhancements to existing features in the Junos OS main release and the maintenance releases for NFX Series.

Release 17.4R3 New and Changed Features

There are no new features or enhancements to existing features for NFX Series in Junos OS Release 17.4R3.

Release 17.4R2 New and Changed Features

There are no new features or enhancements to existing features for NFX Series in Junos OS Release 17.4R2.

Release 17.4R1 New and Changed Features

There are no new features or enhancements to existing features for NFX Series in Junos OS Release 17.4R1.


vSRX version 15.1X49-D100 is compatible with the Junos OS Release 17.4R1 for NFX Series devices.

Changes in Behavior and Syntax

There are no changes in behavior and syntax for NFX Series in Junos OS Release 17.4R2.

Known Behavior

There are no known limitations in Junos OS Release 17.4R3 for NFX Series.

For the most complete and latest information about known Junos OS defects, use the Juniper Networks online Junos Problem Report Search application.

Known Issues

This section lists the known issues in hardware and software in Junos OS Release 17.4R3 for the NFX Series devices.

For the most complete and latest information about known Junos OS defects, use the Juniper Networks online Junos Problem Report Search application.

Virtual Network Functions

  • While spawning a VNF, there might not be a commit check for the valid image type supported. PR1221642

  • If a VNF requests for more memory than the available system memory, commit might go through without any errors resulting in VNF going into a shut off state. As a workaround, use the show system visibility memory command to check the available free memory before spawning a VNF. Alternatively, check the log files and the VNF shut off reason will be captured in /var/log/syslog file. PR1221647

Juniper Device Manager

  • On NFX250 devices, logging in to JDM using TACACS credentials might result in permission denied messages on the shell. This does not have any functional impact. PR1330419

Junos Control Plane

  • If the traffic in the out-of-band interface is more, the control plane connectivity might get blocked for sometime while the packets are processed. If this interruption persists, the connection between the PFE and control plane is cleared, which results in a PFE restart or shutdown. You must ensure that there is no heavy traffic flow in the management VLAN. PR1270689

  • On NFX250 devices, ICMP ping does not work for packets with ICMP payload beyond 1480 bytes. As a workaround, execute the following procedure on both the peer devices:

    1. Issue the set chassis fpc 0 power off command on the virtual control plane (VCP) to power off the FPC.

    2. Access the hypervisor by issuing the rsh ?JU __juniper_private4__ command at the VCP BSD shell.

    3. Set the mtu values on the hypervisor:

      • ip link set hsxe0 mtu 9216

      • ip link set hsxe1 mtu 9216

    4. Verify that the mtu values are set to 9216 by issuing the ip link show hsxe0 | grep mtu and ip link show hsxe1 | grep mtu commands.

    5. Exit from the hypervisor.

    6. Access the Junos CLI and issue the delete chassis fpc 0 power off command.

    7. Wait for the FPC to come up.


Resolved Issues

There are no fixed issues in Junos OS Release 17.4R3 for NFX Series.

Documentation Updates

There are no errata or changes in Junos OS Release 17.4R3 documentation for NFX Series.

Migration, Upgrade, and Downgrade Instructions

This section contains the procedure to upgrade Junos OS, and the upgrade and downgrade policies for Junos OS for the NFX Series. Upgrading or downgrading Junos OS might take several hours, depending on the size and configuration of the network.

Upgrade and Downgrade Support Policy for Junos OS Releases

Support for upgrades and downgrades that span more than three Junos OS releases at a time is not provided, except for releases that are designated as Extended End-of-Life (EEOL) releases. EEOL releases provide direct upgrade and downgrade paths—you can upgrade directly from one EEOL release to the next EEOL release even though EEOL releases generally occur in increments beyond three releases.

To upgrade or downgrade from a non-EEOL release to a release more than three releases before or after, first upgrade to the next EEOL release and then upgrade or downgrade from that EEOL release to your target release.

For more information on EEOL releases and to review a list of EEOL releases, see

Basic Procedure for Upgrading to Release 17.4

When upgrading or downgrading Junos OS, use the jinstall package. For information about the contents of the jinstall package and details of the installation process, see the Installation and Upgrade Guide. Use other packages, such as the jbundle package, only when so instructed by a Juniper Networks support representative.


Back up the file system and the currently active Junos OS configuration before upgrading Junos OS. This allows you to recover to a known, stable environment if the upgrade is unsuccessful. Issue the following command:


The installation process rebuilds the file system and completely reinstalls Junos OS. Configuration information from the previous software installation is retained, but the contents of log files might be erased. Stored files on the router, such as configuration templates and shell scripts (the only exceptions are the juniper.conf and ssh files), might be removed. To preserve the stored files, copy them to another system before upgrading or downgrading the routing platform. For more information, see the Junos OS Administration Library.


We recommend that you upgrade all software packages out of band using the console because in-band connections are lost during the upgrade process.

To download and install Junos OS Release 17.4R3:

  1. Using a Web browser, navigate to the All Junos Platforms software download URL on the Juniper Networks webpage:

  2. Select the name of the Junos OS platform for the software that you want to download.
  3. Select the release number (the number of the software version that you want to download) from the Release drop-down list to the right of the Download Software page.
  4. Select the Software tab.
  5. In the Install Package section of the Software tab, select the software package for the release.
  6. Log in to the Juniper Networks authentication system using the username (generally your e-mail address) and password supplied by Juniper Networks representatives.
  7. Review and accept the End User License Agreement.
  8. Download the software to a local host.
  9. Copy the software to the device or to your internal software distribution site.
  10. Install the new jinstall package on the device.