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Known Issues


This section lists the known issues in hardware and software in Junos OS Release 15.1R7 for the QFX Series.

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


  • In a VXLAN scenario, the Packet Forwarding Engine manager daemon (fxpc) and the kernel might crash after you add an MTU configuration on a QFX5100 Virtual Chassis. PR1283966


  • When the configuration statement set system ports console log-out-on-disconnect is enabled, the Junos OS eventd process (daemon) blocks the console-open(). However, during this stage with the Syslog console configured (always logs on console), any logging continues even if the console session is ended. When the console logging continues to be in the waiting status, the eventd syslog rotation freezes and some processes directly involved in logging in to the system also go into the wait status, causing undesirable behavior. PR1253544

Interfaces and Chassis

  • On QFX5100 switches, with a MAC address and an ARP entry inside an interface block, an error message might be displayed that says an IRB interface and an aggregated Ethernet logical interface do not belong to the same routing instance, even though they do belong to the same routing instance. PR1239191


  • On QFX5100 switches, analyzer is not supported on interfaces with family circuit cross-connect (CCC), which includes encapsulation Ethernet-CCC and encapsulation VLAN-CCC. PR1041780

Routing Protocols

  • On a QFX Series Virtual Chassis, when you explicitly configure an IPv6 firewall filter that discards OSPFv3 packets, the ingress filter might not discard the OSPFv3 packets. PR897786

  • On QFX5100, when resilient hashing is enabled on ECMP paths, flows on other paths should not be rehashed when one path goes down. But for host routes (/32 routes), rehashing might happen in some cases. PR1137998


  • On EX4300, EX4600, and QFX5100 switches, when a VLAN is mirrored, the mirrored packets may contain 38 additional bytes. The IP address in this packet is randomly generated and may appear as one of many existing, valid IP addresses on the Internet. It may appear as ERSPAN as well, which is a proprietary non-Juniper protocol. These addresses and packet types can be ignored. They may appear as alerts in certain IDP / IDS's and in packet analyzer applications, which you can ignore. PR1170589

Spanning Tree Protocols

  • On QFX5100 Virtual Chassis interfaces on which the flexible-vlan-tagging statement is specified, STP, RSTP, MSTP, and VSTP are not supported. PR1075230

Virtual Chassis and Virtual Chassis Fabric

  • On a Virtual Chassis Fabric, Virtual Chassis ports (VCPs) internal traffic looping causing traffic loss might be seen for known multicast traffic with TTL=1. PR1042270

  • A VCF might not communicate properly with the backup spine when it has the configuration parameter forwarding-options enhanced-hash-key fabric-load-balance flowlet configured while upgrading. PR1141965