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Known Issues


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

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

General Routing

  • When a firewall filter is configured on the loopback interface of a PTX Series router, because of a bad error handling or a NULL pointer, all the FPCs on the device might continue to be unresponsive and unstable. Because the issue is not reproducible, the trigger of the issue is not clear. PR996749

  • Starting with Junos 15.1, we experience around 1.3 seconds worth of packet loss for l2ckt traffic ingressing/egressing the router during unified ISSU switchover on PTX5000 platform with broadway chipset FPCs. Prior to 15.1, the packet loss experienced is around 0.5 seconds. PR1102649

  • If only one Routing Engine or Control Board is installed on slot 0 or slot 1 and powered on, leaving the other slot empty, then only the MASTER LED is lit, not the OK LED. If both slots have the Routing Engine and Control Board installed, the problem is not seen, and the MASTER LED glows on the master CB and the OK LED is lit on the backup CB. PR1115148

  • In certain rare conditions, on PTX Series routers, wedging of the FPC virtual output queue (VOQ) causes packets to be dropped on the ingress Packet Forwarding Engine. After the wedge condition is detected, an alarm is raised within 10 seconds. PR1127958

  • PTX 100GbE-LR4 interfaces might flap when the reference clock switches over from being the line clock to operating as the holdover. This switchover and the ensuing interface flapping is initiated when the PIC on which the line-clock sources reside is taken offline. When the router uses line-clock sources and when it does not have any external clocks from BITS-a or BITS-b, offlining the PIC, which is recovering clock from line, brings line-clock down and the reference clock is switched from line-clock to holdover. This reference clock transition might cause a large clock phase-shift in the 100GbE-LR4 CFP modules, and this phase-shift might cause distortion in the output optical pulse waveform on the associated interfaces. This distortion results in interface flapping. This issue cannot be fixed by software because of hardware limitation. PR1130403

  • In a corner case in aggregated Ethernet when the aggregated Ethernet ifd and queue stats are being fetched from SNMP and CLI simultaneously in lieu of events like member being added/removed from config, there might be a temporary drop in stats being reported. This is a transient issue and will go away in the next fetch cycle of stats. PR1176639

  • On PTX Series routers, when the BITS external clock is down or up, an incorrect SNMP trap, jnxFruRemoval(CB), is generated. jnxExtSrcLockAcquired is the correct one. Correct trap: Name: "jnxExtSrcLockAcquired" OID: "" Incorrect trap: Name: "jnxFruRemoval" OID: "" PR1195686

  • A vulnerability in IPv6 processing has been discovered that might allow a specially crafted IPv6 Neighbor Discovery (ND) packet to be accepted by the router rather than discarded. The crafted packet, destined to the router, will then be processed by the Routing Engine. A malicious network-based packet flood, sourced from beyond the local broadcast domain, can cause the Routing Engine CPU to spike, or cause the DDoS protection ARP protocol group policer to engage. When this happens, the DDoS policer might start dropping legitimate IPv6 neighbors as the legitimate ND times out. Refer to JSA10749 for more information. PR1207527

  • On PTX Series routers, when a first-generation or a second-generation FPC is restarted, CoS profiles can be applied incorrectly to certain virtual output queues (VOQs).. This can lead to RED drops on those VOQs for traffic that enters the router on the restarted FPC. PR1211509

  • In Junos OS Release 15.1 and Release 16.1X70-D10, after you run the following command and reboot the router, you can see some error logs on terminal display and messages log. The error messages seem to be a cosmetic issue. === command === set system syslog user * any critical commit After rebooting router. === error message === router-re0 /kernel: GENCFG: op 34 (CLKSYNC blob) failed; err 7 (Doesn't Exist) <<<<<<<< PR1223518

  • The CLI command show route provides an incorrect format of output, displaying the next-hop information in the following format rather than displaying it on the next line: validation-state: unverified, > to 2001:7f8:4::272a:2 via xe-0/0/3.0 PR1254675

  • PTX5000 third-generation FPCs (FPC3-PTX-U3 and FPC3-PTX-U2) using new component will begin shipping from Juniper's factories and Logistics spares depots in March 2018. The new component requires a JUNOS change to operate correctly. If these FPCs are installed in a system running older JUNOS software version without this change, the FPC might fail to boot up. [See TSB17148] PR1258693


  • Multiple negative tests such a restarting routing or chassis-control may cause the router to reboot. PR1077428

Interfaces and Chassis

  • On dual Routing Engine platforms, when you configure the logical interfaces and commit the configuration the device control process (dcd) on the backup Routing Engine might fail to process the configuration and keep it in the memory. In some cases, the memory of the dcd process keeps increasing on the backup Routing Engine. PR1014098

  • Configuring ODU FRR under otn-options for the 2-port 100-Gigabit DWDM PIC is an unsupported command on PTX Series routers. Incorrectly adding such a configuration could result in an FPC crash and restart. PR1038551


  • In an RSVP-based P2MP scenario, if a sub-LSP switchover to bypass LSP due to PIC offline, then when a new sub-LSP is established via setup-protection, the deletion of the old sub-LSP might result in deletion of both sub-LSPs. PR1132050

Platform and Infrastructure

  • With sampling configured, if AS paths change, over a period of time in the network, the stale AS paths might be seen in the sampler database of JNH memory. PR1189689

  • On PTX Series platform with network-services enhanced-mode configured at the [edit chassis] hierarchy level, the default policy junos-ptx-series-default is not loaded correctly during some configuration operations, which causes BGP routes not to be installed in the forwarding table as expected. To avoid this issue, reboot the router after any configuration operations on network services. PR1204827

Routing Protocols

  • When there are two paths for the same route, the route gets pointed to the unilist next hop, which in turn gets pointed to two separate unicast next hops. The route is determined by OSPF, and BFD is enabled on one of the paths, which runs through a Layer 2 circuit path. When the link on the Layer 2 circuit gets cut, the link flapping is informed by BFD as well as through OSPF LSAs. Ideally, BFD should inform the link-down event before the OSPF LSA. But currently, the OSPF LSAs update the current event a second before BFD. Because of this reason, the route needs to point to a new unilist next hop with the weights swapped. But the unicast next hop for which the L3 link is down gets added to the unilist next hop BFD assumes the link to be up, and hence updates the weights inappropriately; as a result, a traffic loss is observed. After the BFD link-down event is processed at the OSPF protocol level, the route points only to the unicast next hop; therefore, traffic flows through the currently active link. The traffic outage would be less than a second during FRR. This issue can be avoided if the BFD keepalive intervals are maintained around 50 ms with a multiplier of 3 as opposed to 100 ms with a multiplier of 3. PR1119253

  • In a multicast environment, if the rendezvous point (RP) is a first-hop router and has MSDP peers, when the rpf interface on the RP changes to an MSDP-facing interface, a multicast discard route is installed and traffic loss is experienced because multicast traffic is still on the old rpf interface. PR1130238

  • With Shared Risk Link Group (SRLG) enabled under corner conditions, after executing the clear isis database command, the rpd might crash because the IS-IS database tree gets corrupted. PR1152940

  • IS-IS might flap during Routing Engine switchover. PR1163770

  • When multiple labels become stale in stale-label-holddown-duration (default 60 seconds), it restarts the timer and accumulates all the stale-labels without getting deleted. This might cause memory for allocating labels to be exhausted and then MPLS traffic might be affected because of abnormal or faulty label allocation. PR1211010

  • The rpd process might crash if the IS-IS process tries to send out packets when flow control is not ready. PR1214947

  • On devices running Junos OS with the graceful restart enabled, the restarting node might send the "End of RIB" maker too soon to its helper nodes, before the actual route updates are completed, and thereby causing traffic loss. PR1225868