After downgrading the QFX5100 switch from Junos OS version 14.1X53-D47.3 to Junos OS 14.1X53-D28.15, the switch may be seen to generate the fxpc core continuously, while reporting PANIC errors on the console. This problem can be seen in stand-alone mode and in virtual-chassis mode of operation.
Note: The errors are seen until the switch is upgraded again to Junos OS release 14.1X53-D47.3.
In this article, the cause for the PANIC errors to be reported is given, along with the solution.
The following errors are seen on the console after the software downgrade:
Message from syslogd@Juniper at Mar 2 05:34:31 2019 ... Juniper dc-pfe: Registers: Message from syslogd@Juniper at Mar 2 05:34:31 2019 ... Juniper dc-pfe: eip: 0x08f400c2 eflags: 0x00000246 trapno: 0 Message from syslogd@Juniper at Mar 2 05:34:31 2019 ... Juniper dc-pfe: eax: 0x00000054 ebx: 0x00000000 ecx: 0x58813f95 edx: 0x00000054 Message from syslogd@Juniper at Mar 2 05:34:31 2019 ... Juniper dc-pfe: esi: 0x00000000 edi: 0x00000000 esp: 0x217d77b8 ebp: 0x217d77e0 Message from syslogd@Juniper at Mar 2 05:34:31 2019 ... Juniper dc-pfe: cs: 0x0033 ds: 0x20c3003b es: 0x003b fs: 0x003b gs: 0x001b ss: 0x003b Message from syslogd@Juniper Mar 2 05:34:31 2019 ... Juniper dc-pfe: Message from syslogd@Juniper at Mar 2 05:34:31 2019 ... Juniper dc-pfe: PANIC PANIC PANIC PANIC PANIC PANIC Message from syslogd@Juniper at Mar 2 05:34:31 2019 ... Juniper dc-pfe: Watchdog fired delta=3 sig_watchdog_counter=10 watchdog_counter=10 Message from syslogd@Juniperat Mar 2 05:34:31 2019 ... Juniper dc-pfe: Traceback: Message from syslogd@Juniper at Mar 2 05:34:31 2019 ... Juniper dc-pfe: Frame 0: sp = 0x217d7418, pc = 0x8048ada Message from syslogd@Juniper at Mar 2 05:34:31 2019 ... Juniper dc-pfe: Frame 1: sp = 0x217d7428, pc = 0x806bc5e Message from syslogd@Juniper at Mar 2 05:34:31 2019 ... Juniper dc-pfe: Frame 2: sp = 0x217d7448, pc = 0x806bca8
The core dump is seen as below:
> show system core-dumps fpc0: -------------------------------------------------------------------------- -rw-rw---- 1 root field 3724275 Mar 2 05:33 /var/tmp/fxpc.core.0.gz -rw-rw---- 1 root field 3737886 Mar 2 05:36 /var/tmp/fxpc.core.1.gz -rw-rw---- 1 root field 3747609 Mar 2 05:37 /var/tmp/fxpc.core.2.gz -rw-rw---- 1 root field 3781011 Mar 2 05:38 /var/tmp/fxpc.core.3.gz -rw-rw---- 1 root field 2261002 Mar 2 06:15 /var/tmp/fxpc.core.4.gz
This issue is caused when there is a mismatch between the Junos OS host software version and the version that is currently used on the switch.
Hostname: Juniper Model: qfx5100-96s-8q Junos: 14.1X53-D28.15 JUNOS Base OS Software Suite [14.1X53-D28.15] JUNOS Base OS boot [14.1X53-D28.15] JUNOS Crypto Software Suite [14.1X53-D28.15] JUNOS Online Documentation [14.1X53-D28.15] JUNOS Kernel Software Suite [14.1X53-D28.15] JUNOS Packet Forwarding Engine Support (qfx-ex-x86-32) [14.1X53-D28.15] JUNOS Routing Software Suite [14.1X53-D28.15] JUNOS Enterprise Software Suite [14.1X53-D28.15] JUNOS Web Management Platform Package [14.1X53-D28.15] JUNOS py-base-i386 [14.1X53-D28.15] JUNOS Host Software [14.1X53-D47.3]
To ensure that the Junos OS version and the host software version are the same, use the force-host option while downgrading the switch.
force-host
>request system software add <upgrade image file name and location> force-host