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Known Limitations

Learn about known limitations in this release for QFX Series switches.

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


  • Junos OS 21.1 and earlier releases are running on FreeBSD version 11, whereas Junos OS 21.2 and later releases use the FreeBSD version 12. Software upgrade to Junos OS 21.2 or later from Junos OS 21.1 or earlier must use the no-validate statement during software image upgrade process. PR1586481

Platform and Infrastructure

  • The Junos OS might get hang when trying to acquire the SMP IPI lock while rebooting when it is running as a VM on the Linux and QEMU hypervisor. Device can be recovered using power-cycle of the device. PR1385970

  • Error logs are expected when routes point to the target next hop, which in turn point to hold next hops. These error logs are present for a short time. Later, when the next hop changes from a hold next hop to valid next hop, unilist next hops will be walked again and updated with the appropriate weight and reroute counters, and no more error logs will be seen. PR1387559

  • On a fully scaled system where all the slices are utilized by different families of CLI filters, if you try to delete one family and change another family with higher number of filter terms that requires expansion of the filter, the Packet Forwarding Engine fails to add the new changed filter as out of sequence messages are generated, that is, change of filter is called earlier than deletion of another filter. PR1512242

  • On QFX5200 and QFX5100 devices with the IP-IP tunnel feature, the show dynamic-tunnels database statistics command output shows extra packers counts. That is, sampled packets when sFlow is enabled. PR1555922

  • On QFX5120 Series platforms, IRACL filters might not be able to match on VXLAN tunnel terminated packets. PR1594319

  • On QFX5100 switches, the overall device utilization and FPC CPU utilization might be high in case of 4093 Irb with full port density (32/24). It might differ by maximum 4-5 percent compare to the same system having very less port density (1 or 2 ports). Some of the FPC threads takes more CPU in such scenario (for example, Ethernet and QSFP). PR1595029

  • sFlow in an EVPN VXLAN IPv4 underlay, outgoing interface (OIF) will be reported as zero for ingress sampling when packet goes out through ECMP next hops. PR1608121