Known Limitations

Learn about known limitations in this release for MX Series routers.

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 the MX2000 line of routers, you might see RPD usage hit 100% when you start running OCST polling. The spike in RPD usage is expected because of the very large scale and OCST in general. This issue should not affect any RPD functionality if that is the concern since telemetry streaming is the lowest priority task in RPD. PR1614978
It is recommended to use IGP shortcut with strict SPF SIDs in SRTE path. if Strict SPF SIDs are used then this issue would not occur. This issue will occur only if regular ISIS SIDs are used in SRTE path and IGP shortcut is enabled. with this, if customer perform multiple times deactivate/activate for SRTE telemetry.PR1697880
On older MPC Cards (for example, MPC6) that have PPC as the host CPU, the CPU usage can exceed 95% whenever the host-bound traffic rate is more than 5k-6k PPS. SNMP polling consumes a significant amount of CPU resources; disabling it will allow the system to handle some amount of additional PPS host-bound traffic. In current PR context, disabling SNMP allowed the system to handle an additional 2k-3k PPS of host-bound traffic. When the CPU usage is greater than 95 percent, host-bound routing protocol packets (for example, BGP and ISIS) may not be drained fast enough, which may result in flaps. PR1749829

Juniper Routing-Engines with HAGIWARA CF card installed, after upgrade to 15.1 and later releases, the failure message about "smartd[xxxx]: Device: /dev/ada1, failed to read SMART Attribute Data" might appear on messages log. PR1333855
When upgrading from releases before Junos OS Release 21.2 to Release 21.2 and onward, validation and upgrade might fail. The upgrade requires using the 'no-validate' option to complete successfully. https://kb.juniper.net/TSB18251PR1568757