Deleting a subinterface that has IPv6 EIGRP running on it and crashing IOS XE
In some cases router running IOS XE might crash or produce traceback if we try to delete logical interface (like ie. port-channel) or subinterface that runs IPv6 EIGRP. This can occur mostly on XNE or older releaseses, has been fixed in new ones. Cisco have internal bug CSCtd63242 describing this problem (might be released into public).
For testing purposes I prepared following configuration
interface Port-channel1 no ip address no negotiation auto ! interface Port-channel1.282 encapsulation dot1Q 282 ip address 10.0.0.1 255.255.255.240 ipv6 address 2A01:3D0:1:212::1/64 ipv6 enable ipv6 eigrp 150 !
Let’s try to remove configuration
test-rtr(config)#no int port-ch 1 test-rtr(config)# Exception to IOS Thread: Frame pointer 2C64F498, PC = 116D5838 ASR1000-EXT-SIGNAL: U_SIGSEGV(11), Process = EIGRP-IPv6 -Traceback= 1#da7989e8973511c6ffbd1828e9ed3784 :10000000+16D5838 systime:B4E7000+19D0 :10000000+16D5A94 :10000000+629B9C :10000000+641A28 :10000000+3F1F108 :10000000+3F1F870 :10000000+3F200E4 Fastpath Thread backtrace: -Traceback= 1#da7989e8973511c6ffbd1828e9ed3784 c:B20A000+D8678 c:B20A000+D8658 iosd_unix:B38C000+1247C pthread:AFB8000+56EC Auxiliary Thread backtrace: -Traceback= 1#da7989e8973511c6ffbd1828e9ed3784 pthread:AFB8000+B168 pthread:AFB8000+B148 c:B20A000+EDEB4 iosd_unix:B38C000+1BEE4 pthread:AFB8000+56EC PC = 0x116D5838 LR = 0x116D5A94 MSR = 0x0002D000 CTR = 0x0B4E89C0 XER = 0x00000000 R0 = 0x116D5A94 R1 = 0x2C64F498 R2 = 0x2C0619D0 R3 = 0x0D0D0D0D R4 = 0x2C64F4C8 R5 = 0x00000004 R6 = 0x10629B98 R7 = 0x00000000 R8 = 0x03BC53F5 R9 = 0x00000000 R10 = 0x00000001 R11 = 0x00000000 R12 = 0x03BC53F4 R13 = 0x15B09550 R14 = 0x13F1FDB4 R15 = 0x00000000 R16 = 0x00000000 R17 = 0x00000000 R18 = 0x00000000 R19 = 0x00000000 R20 = 0x00000000 R21 = 0x13F20000 R22 = 0x2C64F5E8 R23 = 0x15240000 R24 = 0x153E0000 R25 = 0x15E90000 R26 = 0x2C647BE0 R27 = 0x00000000 R28 = 0x2C64F4C8 R29 = 0x10629B98 R30 = 0x00000004 R31 = 0x0D0D0D0D Writing crashinfo to bootflash:crashinfo_RP_00_00_20110801-230510-UTC Buffered messages: 000060: *Aug 1 06:34:36.421 UTC: %LINEPROTO-5-UPDOWN: Line protocol on Interface Loopback0, changed state to up 000061: *Aug 1 06:35:15.252 UTC: %LINEPROTO-5-UPDOWN: Line protocol on Interface Port-channel1, changed state to down 000062: *Aug 1 06:36:33.701 UTC: %SYS-5-CONFIG_I: Configured from console by console 000063: *Aug 1 06:36:53.770 UTC: %SYS-5-CONFIG_I: Configured from console by console 000064: *Aug 1 06:37:26.149 UTC: %SYS-5-CONFIG_I: Configured from console by console 000065: *Aug 1 06:37:27.859 UTC: %LINK-3-UPDOWN: Interface GigabitEthernet0/0/0, changed state to up 000066: *Aug 1 06:37:28.859 UTC: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0/0, changed state to up 000067: *Aug 1 06:37:27.932 UTC: %LINK-3-UPDOWN: SIP0/0: Interface GigabitEthernet0/0/0, changed state to up 000068: *Aug 1 06:48:50.464 UTC: %SYS-5-CONFIG_I: Configured from console by console 000069: *Aug 1 06:51:37.651 UTC: %SYS-5-CONFIG_I: Configured from console by console 000070: *Aug 1 07:06:52.608 UTC: %SYS-6-EXEC_EXPIRE_TIMER: (tty 0 (0.0.0.0)) exec-timeout timer expired for user 000071: *Aug 1 22:49:29.616 UTC: %SYS-5-CONFIG_I: Configured from console by console 000072: *Aug 1 23:03:52.064 UTC: %LINK-5-CHANGED: Interface GigabitEthernet0/0/0, changed state to administratively down 000073: *Aug 1 23:03:53.064 UTC: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0/0, changed state to down 000074: *Aug 1 23:04:02.488 UTC: %LINK-3-UPDOWN: Interface GigabitEthernet0/0/0, changed state to up 000075: *Aug 1 23:04:03.488 UTC: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0/0, changed state to up 000076: *Aug 1 23:04:02.530 UTC: %LINK-3-UPDOWN: SIP0/0: Interface GigabitEthernet0/0/0, changed state to up 000077: *Aug 1 23:04:08.230 UTC: %SYS-5-CONFIG_I: Configured from console by console Queued messages:Aug 1 23:06:41.536 R0/0: %PMAN-3-PROCHOLDDOWN: The process ppc_linux_iosd-image has been helddown (rc 139) Aug 1 23:06:41.742 R0/0: %PMAN-0-PROCFAILCRIT: A critical process ppc_linux_iosd_image has failed (rc 139) Aug 1 23:06:41.914 R0/0: %PMAN-3-RELOAD_RP_SB_NOT_READY: Reloading: Fault on Active RP bay but Standby RP bay is not ready Aug 1 23:06:48.762 R0/0: %PMAN-5-EXITACTION: Process manager is exiting: critical process fault, ppc_linux_iosd_image, rp_
What’s interested
There are two things we can do except recommended upgrade:
1) Remove EIGRP configuration from the subinterface with a before deleting the subinterface
2) Activate software redundancy (additional license is required) so software crash would cause only switchover to redundant IOS process.