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Known Limitations

Learn about known limitations in Junos OS Release 21.4R2 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.

General Routing

  • On QFX1000 devices, source MAC and TTL values are not updated for routed multicast packets in EVPN-VXLAN. PR1346894

  • On the QFX5000 devices with storm control, there is a significant difference between the configured rate and the actual rate. PR1526906

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

  • On QFX5000 devices, in EVPN-VXLAN deployment, Broadcast, Unknown Unicast, and Multicast (BUM) traffic replication over VTEP might send out more packets than expected. PR1570689

  • On QFX5000 devices, IRACL filters are unable to match the VxLAN tunnel terminated packets. PR1594319

  • The 1pps performance test fails on the copper ports.PR1618533

  • When the IFA2.0 init feature enabled on the device and flows are sampled, incorrect pps and bps statistics gets displayed at the logical child interface level on the ingress and egress ports. PR1620139

  • Junos OS does not support the unified ISSU on QFX5120-48Y devices if there is a change in the Cancun versions of the chipset SDKs between the releases. A change in the Cancun firmware leads to the chip reset impacting unified ISSU. The Cancun versions in the chipset SDKs must be the same between two Junos OS releases for unified ISSU to work.PR1634695


  • Software image upgrade from Junos OS Release 21.1 (or earlier) to Junos OS Release 21.2 (or later) requires no-validate command as a mandatory action. PR1586481