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Known Limitations


Learn about limitations in this release for the QFX5220. For the most complete and latest information about known Junos OS Evolved defects, use the Juniper Networks online Junos Problem Report Search application.


  • Linkscan status reflects correctly and Interface state gets updated accordingly, but the RxLOS alarm gets set sometimes randomly even after link goes down. PR1404144

  • In an MPLS network where the QFX5220 acts as MPLS PE or P router, traffic loss can be seen during FRR triggers like node/link failure. The duration of the loss depends on the number of routes and next-hops in the switch and varies between 300 milliseconds to 1 second PR1416946

  • During frequent route updates or link flaps, the system may not achieve the full scale of 4K ECMP next-hops. PR1419943

  • Available Firmware version for all non supported firmware upgrade components will be shown as 0 in system firmware output. Firmware components not supported are TMC FPGA and CPLD components. Also there are redundant values shown under CHASSIS and RE for all the firmware components. PR1422023

  • When the dis is Full , we should get an alarm indicating disk partition is Full to avoid re-writes / slowness in performance PR1428750

  • The following XML tags are missing in Junos OS Evolved for the show system buffers CLI: <memory-statistics>, <current-mbufs>, <cached-mbufs>, <total-mbufs>, <current-mbuf-clusters>, <cached-mbuf-clusters>, <total-mbuf-clusters>, <max-mbuf-clusters>, <packet-count>, <packet-free>, <current-jumbo-clusters-4k>, <cached-jumbo-clusters-4k>, <total-jumbo-clusters-4k>, <max-jumbo-clusters-4k>, <current-jumbo-clusters-9k>, <cached-jumbo-clusters-9k>, <total-jumbo-clusters-9k>, <max-jumbo-clusters-9k>, <current-jumbo-clusters-16k>, <cached-jumbo-clusters-16k>, <total-jumbo-clusters-16k>, <max-jumbo-clusters-16k>, <current-bytes-in-use>, <cached-bytes>, <total-bytes>, <mbuf-failures>, <cluster-failures>, <packet-failures>, <jumbo-cluster-failures-4k>, <jumbo-cluster-failures-9k>, <jumbo-cluster-failures-16k>, <sfbuf-requests-denied>, <sfbuf-requests-delayed>, <io-initiated>. PR1429626

  • There are differences in xml tags for cli "show system directory-usage." PR1429629

  • Fragmentation doesn't happen for IPv4 packets on transit Junos Evolved-based devices when the outgoing MTU is less than the packet size. The packet is dropped. PR1429634

  • For cli show system uptime, there are output xml tag differences compared to Junos. PR1429636

  • The following XML tags are missing in Junos OS Evolved for the show system virtual-memory CLI: <system-virtual-memory-information> <vmstat-memstat-malloc> <vmstat-memstat-info> <memstat-name> <inuse> <memuse> <high-use> <memstat-req> <memstat-size> <vmstat-memstat-zone> <vmstat-zone-info> <zone-name> <zone-size> <count-limit> <used> <free> <zone-req> <vmstat-sumstat> <cpu-context-switch> <dev-intr> <soft-intr> <traps> <sys-calls> <kernel-thrds> <fork-calls> <vfork-calls> <rfork-calls> <swap-pageins> <swap-pagedin> <swap-pageouts> <swap-pagedout> <vnode-pageins> <vnode-pagedin> <vnode-pageouts> <vnode-pagedout> <page-daemon-wakeup> <page-daemon-examined-pages> <pages-reactivated> <copy-on-write-faults> <copy-on-write-optimized-faults> <zero-fill-pages-zeroed> <zero-fill-pages-prezeroed> <transit-blocking-page-faults> <total-vm-faults> <page-faults-requiring-io> <pages-affected-by-kernel-thrd-creat> <pages-affected-by-fork> <pages-affected-by-vfork> <pages-affected-by-rfork> <pages-cached> <pages-freed> <pages-freed-by-deamon> <pages-freed-by-exiting-proc> <pages-active> <pages-inactive> <pages-in-vm-cache> <pages-wired-down> <pages-free> <bytes-per-page> <total-name-lookups> <positive-cache-hits> <negative-cache-hits> <pass2> <cache-deletions> <cache-falsehits> <toolong> <vmstat-intr> <vmstat-intr-info> <intr-name> <intr-cnt> <intr-rate> <vm-kernel-state> <vm-kmem-map-free> PR1429639

  • It takes up to 600s in QFX5220-128C for interfaces to come up after reboot when all ports are channelized. The time taken is around 520 without channelization of interfaces. The higher time is due to the time taken to download firmware to all 64 dies PR1433083

  • The following XML tags are missing in Junos OS Evolved for the show system queues CLI: <queues-statistics> <interface-queues-statistics> <interface-queue> <name> <octets-in-queue> <max-octets-allowed> <packets-in-queue> <max-packets-allowed> <number-of-queue-drops> <protocol-queues-statistics> <protocol-queue> PR1433449

  • While doing channelization (4x25G or 4x10G) with only the following config (for example): # "set chassis fpc 0 pic 0 port 20 speed 25g number-of-sub-ports 4", only ONE sub-channel IFD will be created which is "et-0/0/20:0". Rest of the sub-channel IFDs will NOT be created. And also no ERROR is shown. PR1433586

  • After dechannelization/channelization of 100G to 25G, one interface remains in the down state. PR1434534

  • While doing channelization, with 1st committing the "channelized" config of port and then followed by "unused" config on subsequent ports, the sub-channel IFDs might stay down. For example: IF FOR channelization (4x25G or 4x10G) on port 20 with the following config done 1st: # set chassis fpc 0 pic 0 port 20 speed 25g number-of-sub-ports 4 # commit AND THEN followed by the "unused" config on sub-sequent ports like below: # set chassis fpc 0 pic 0 port 21 unused # set chassis fpc 0 pic 0 port 22 unused # set chassis fpc 0 pic 0 port 23 unused # commit THEN , the sub-channel IFDs might stay down. PR1434584

  • TrafficControlProfile could trigger code dump, this is unsupported feature. PR1437319

  • 40G interface stays down after configuring the correct speed when the very next port has 100G optics/DAC plugged in. And after the reboot the same 40G link comes UP and the 100G link goes down. PR1437700

  • With unknown unicast traffic is transmitted from all the ports at line rate totaling 12.8 TBPS for system , packet drops are expected till frame size 1200 bytes. PR1441632

  • SW to update PR1446214

  • interfaces will disappear if configure interfaces speed as 25g and interface will remain (but not disappear) if config the speed as 40g. PR1447775

  • evo-pfemand application utilises 100% CPU for 10-15 mins when evo-pfemand app is restarted with channelized configuration , during this time few of the cli command o/p might be sluggish . PR1447849

  • channelized interfaces went down with config /delete with unused config in separate or config channelized port without config other 3 ports in block to unused will lead to interface down or missing interface issue. PR1448451

  • QFX5220-128C: Interfaces OIR might take up 50 seconds to come up on 19.2R1 release. PR1449416

General Routing

  • After few triggers we see this core. There wont be any impact to system, ipv6 traffic will restore. Triggers: AE members: delete-add, deactivate-activate, disable-enable AE: delete-add, disable-enable, deacitvate-activate clear rsvp, bgp, OSPF, ospf3, arp database, neighbors deactivate-activate protocols restart ifmand , lacpd , configd, ppmd, ndp, ifstatsd, arpd, clear arp, interface stats all MTU change <<< cores observed at this time PR1449071


  • When USB is plugged in, image is not picked from the USB in the boot-order by default. PR1399311

Multiprotocol Label Switching (MPLS)

  • As Broadcom TH3 chipset has a label space of only 8000, the next-hop scale is limited to approximate 7500. Beyond this next-hop programming may fail and result in traffic drop. PR1416624

Routing Policy and Firewall Filters

  • A mustd core will be seen if filter based GRE decap is configured in the 19.2R1-EVO image.This feature is not supported in 19.2R1-EVO. PR1443692

User Interface and Configuration

  • Junos OS Evolved uses the request system shutdown (reboot | power-off | halt) commands. This is different than the Junos commands for same functionality.

  • Executing the CLI 'show version and haiku' causes the CLI session to quit abruptly. There is no functional impact to the device. A new CLI session can be started to continue working on the device. PR1448486