Help us improve your experience.

Let us know what you think.

Do you have time for a two-minute survey?


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.


  • The Junos OS Release 21.2 is in stable12 BSD release and there is a limitation where image validation is not supported across different BSD versions. Image validation fails from stable11 to stable12. For upgrade between different BSD releases, you need to use no-validate option. PR1568757

Platform and Infrastructure

  • Junos OS might hang trying to acquire the SMP IPI lock while rebooting when it is running as a virtual machine on Linux and QEMU hypervisor. PR1385970

  • The issue occurs because of a PECHIP limitation when underlay is tagged. After de-encapsulation, when the inner packet is recirculated, it still retains the VLAN tag property from outer header because the outer header was tagged. Thus 4 bytes of inner tag got overwritten in the inner packet and the packet got corrupted, which will result in EGP chksum trap seen in PECHIP. As a workaround, enable the encapsulate-inner-vlan configuration. PR1435864

  • On QFX10002 switches in a dynamic IP-IP tunnel transit scenario, when sFlow egress sampling is enabled on an aggregated Ethernet interface in an ECMP case, the sFlow export data does not include the next hop field. PR1533307

  • On QFX5100 devices that runs on the qfx-5e codes, when an image with the third party SDK upgrade (6.5.x) is installed, the CPU utilization might go up by around 5 percent. PR1534234

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

  • On QFX10002-72Q switches, configuration validation is not supported during an image downgrade or upgrade. PR1579050

  • With the multicast sampling enabled, some packets might be dropped when samples received from the hardware matches the multicast replication rate configured. PR1586690

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

Routing Protocols

  • On QFX5120-48YM switches, when the scale of IPv4 and IPv6 routes are present in the LPM profile, a few of the IPv6 routes do not get installed when the ports on which the routes are learnt flaps due to the LPM table full error. PR1557655