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Open Issues

Learn about open issues in Junos OS Rlease 21.4R1 for PTX 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 PTX Platform with FPC-PTX-P1-A or FPC2-PTX-P1A, you might encounter a single event upset (SEU) event that might cause a linked-list corruption of the TQCHIP. The following syslog message gets reported: Jan 9 08:16:47.295 router fpc0 TQCHIP1: Fatal error pqt_min_free_cnt is zero Jan 9 08:16:47.295 router fpc0 CMSNG: Fatal ASIC error, chip TQ Jan 9 08:16:47.295 router fpc0 TQ Chip::FATAL ERROR!! from PQT free count is zero jan 9 08:16:47.380 router alarmd[2427]: Alarm set: FPC color=RED, class=CHASSIS, reason=FPC 0 Fatal Errors - TQ Chip Error code: 0x50002 Jan 9 08:16:47.380 router craftd[2051]: Fatal alarm set, FPC 0 Fatal Errors - TQ Chip Error code: 0x50002 Junos OS chassis management error handling does detect such condition, and raises an alarm and performs the disable-pfe action for the affected Packet Forwarding Engine entity. To recover this Packet Forwarding Engine entity, a restart of the FPC is needed. Contact your Juniper support representative if the issue persists even after the FPC restarts. PR1254415

  • On the PTX Series platform using indirect next hop (such as Unilist) as route next hop type for multiple paths scenario (such as BGP PIC or ECMP), the fast reroute session might be enabled in Packet Forwarding Engines. When the version-id or session-id of the indirect next hop is above 256, the Packet Forwarding Engine might not respond to session update, which might cause the session-id to be stuck permanently with the weight of 65535 in the Packet Forwarding Engine. This might lead the Packet Forwarding Engine to have a different view of Unilist against load-balance selectors. Then, either the BGP PIC or the ECMP-FRR might not work properly and traffic might be dropped or silently discarded. PR1501817

  • On Junos PTX platforms, the Jflow service might not report the accurate throughput rate. This issue is seen when there is high sampled traffic rate with low flow cache hit ratio. PR1502645

  • Flapping may be observed on channelized ports of PTX Series routers during ZTP when one of the ports is disabled on the supporting device. PR1534614

  • A vulnerability in the handling of exceptional conditions in Juniper Networks Junos OS Evolved allows an attacker to send specially crafted packets to the device, causing the Advanced Forwarding Toolkit manager (evo-aftmand-bt or evo-aftmand-zx) process to crash and restart, impacting all traffic going through the FPC, resulting in a Denial of Service (DoS). Please refer to for more information. PR1572969

  • On PTX10000 platforms running Junos OS, file permissions might be changed for /var/db/scripts files after rebooting the device. This issue might have an impact on the scripts running on the box. PR1583839

  • When the interface transitions from down to up, the carrier transition counter value of a particular interface can be incorrect when the peer interface takes longer time to come up. Configuring hold-time for up and down helps to resolve. PR1601946

  • On all PTX platforms, when a Provider Edge (PE) router is configured with multipath, traffic loss might be seen even though the link is up. After the fix, no-ifl-based-frr-for-inh-primary can be applied under routing-option to evade such issue. PR1618507

  • On dual Routing Engine PTX5000 platforms equipped with SPMB type- PTX5000 CB PMB, immediately after a switchover, if the new primary SPMB (Switch Processor Mezzanine Board) finds any CB-to-SIB PCI (Control Board - Switch Interface Board Peripheral Component Interconnect) link down error, then the new primary SPMB might crash causing a traffic blackhole for about 2-3 minutes while the SIBs (Switch Interface Board) are re-initialized. PR1637950

Interfaces and Chassis

  • After USB upgrade, primary role is getting resolved but FPC's are not coming online. PR1637636


  • On PTX3000 routers, if RPD thrashes during a GRES switchover, there might be traffic loss on MPLS LSPs. PR1590681

Platform and Infrastructure

  • On PTX platforms, if BGP sessions are activated or deactivated in all the devices, a kernel crash might be seen. PR1602442

Routing Protocols

  • When IS-IS database is cleaned, rpd crash might be observed. PR1631738