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 Junos OS Release 21.3R2 for EX 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 Release 21.1 and prior runs FreeBSD version 11 whereas from Junos OS Release 21.2 and later runs FreeBSD version 12. Software upgrade to Junos OS Release 21.1 (or later) from 21.1 (or prior) needs the no-validate command to be used during the software image upgrade process. (For EX4400 switches, this is applicable from Junos OS Release 21.3 and later.) PR1586481

Platform and Infrastructure

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

  • Error logs get generated 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, the unilist next hops walks again, gets updated with the appropriate weight, and reroute counters. Later, no error logs get generated. PR1387559