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Known Behavior


This section lists known behavior, system maximums, and limitations in hardware and software in Junos OS Release 17.2R2 for the QFX Series.

For the most complete and latest information about known Junos OS problems, use the Juniper Networks online Junos Problem Report Search application.


  • A PE device running EVPN IRB with an IGP configured in a VRF associated with the EVPN instance will be unable to establish an IGP adjacency with a CE device attached to a remote PE. The IGP instance running in the VRF on the PE may be able to discover the IGP instance running on the remote CE through broadcast or multicast traffic, but will be unable to send unicast traffic directly to the remote CE. Workaround: Run IGP sessions between aPE and locally attached CEs. Use L3VPN to distribute the IGP-learned routes between PEs across the core. PR977945

High Availability (HA) and Resiliency

  • On QFX5100 switches, residual and baseline statistics loss from unified ISSU—Using unified ISSU to upgrade to Junos OS Release 17.2R1 or later will result in a loss of residual and baseline statistics for interfaces, interface set specific statistics, and BBE subscriber service statistics because of an update to the statistics database.

    [See Unified ISSU System Requirements.]

Interfaces and Chassis

  • If port speed is changed in from 25G to 100G or there are repeated changes in port speed settings, then the link may remain down. This is a Broadcom SDK limitation and has been addressed in Broadcom SDK versions 6.5.8 and earlier. Workaround: If repeated port speed change caused the links to remain down, then delete the configuration once and reconfigure to restore the port link status. PR1250891

Virtual Chassis

  • If a QFX5100 switch running Junos OS Release 17.2R1 or later is in the same Virtual Chassis or Virtual Chassis Fabric (VCF) as a Juniper Networks device that does not support Virtual Extensible LAN (VXLAN) for example, an EX4300 switch, then the Junos OS CLI of the EX4300 switch supersedes the Junos OS CLI of the QFX5100. As a result, the vxlan configuration statement at the [edit vlans vlan-name] hierarchy level does not appear. PR1176054