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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.

General Routing

  • Junos OS does not support the Unified ISSU on QFX5120-48Y switches if there is a change in the Cancun versions of the chipset SDKs between the releases. This is a product limitation as change in the Cancun firmware leads to the chip reset and hence ISSU is impacted. The Cancun versions in the chipset SDKs should be the same between two JUNOS OS releases for ISSU to work. PR1634695

  • When EVPN-VxLAN tunnel gets established over IPv6 underlay, the encapsulated packets emitted out of leaf node (QFX10000) might have UDP checksum zero. This is the default behavior of all IPv6 tunneled UDP packets and it is allowed as per RFC6936. PR1656363


  • When upgrading from Junos OS release 21.2 prior and later, validation and upgrade fails. You must use the no-validate command while upgrading. PR1568757