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Downgrade ASR 9010 IOS 5.1.2 [default] to IOS 4.2.1


Hi Forum,


Ive a problem downgrading ASR 9010 from IOS 5.1.2 to 4.2.1. due to documentation theres no SMU to downgrade these IOS.

the ASR 9010 have dual RSP-440-TR and MOD80-TR, the downgrade was successful but the LC MOD80-TR wasnt "UP" -> MBI Booting looping.


is there any miss step on those downgrade procedure?




Cisco Employee
Cisco Employee



We do not support downgrading from 4.3.0+ to pre-4.3.0 due to architectural changes in the images. While the system allows you to do this and its entirely possible it will have no visible effect sometimes it does, and other times an issue may lurk in the background and appear later on; so really its best to just not do this.


There are two ways to downgrade in this case:

1. We can turboboot to 4.2.1

2. After the 'install activate' (assuming you were upgrading 4.2.1 to 5.1.2) and router reload wait until all services are confirmed and then issue 'install commit', if a rollback is needed simply reboot and the router will go back to the old image as the 5.1.2 image is not committed yet.


As for the bootloop can you paste the console logs?




Hi Sam,


thanks for reply my post before.


okay, actually this is the requirement of our customer. but, its that a different architecture? ive read the minimum release on my LC[ASR9K-MOD80-TR and RSP-440-TR] are supported by those release. but, i dont see the LC goes UP.

heres the log for LC doesnt UP.

RP/0/RSP1/CPU0:ios#sh logging last 15
Thu Nov  6 23:44:54.667 UTC
Syslog logging: enabled (0 messages dropped, 0 flushes, 0 overruns)
    Console logging: level warnings, 11 messages logged
    Monitor logging: level debugging, 0 messages logged
    Trap logging: level informational, 0 messages logged
    Buffer logging: level debugging, 77 messages logged

Log Buffer (307200 bytes):

RP/0/RSP1/CPU0:Nov  6 23:41:30.507 : canb-server[150]: %PLATFORM-CANB_SERVER-7-CBC_PRE_RESET_NOTIFICATION : Node 0/0/CPU0, Power Cycle (0x05000000)  
RP/0/RSP1/CPU0:Nov  6 23:41:30.508 : shelfmgr[375]: %PLATFORM-SHELFMGR-6-NODE_STATE_CHANGE : 0/0/CPU0 A9K-MOD80-TR state:ROMMON 
RP/0/RSP1/CPU0:Nov  6 23:41:30.518 : canb-server[150]: %PLATFORM-CANB_SERVER-7-CBC_PRE_RESET_NOTIFICATION : Node 0/1/CPU0, Power Cycle (0x05000000)  
RP/0/RSP1/CPU0:Nov  6 23:41:30.525 : shelfmgr[375]: %PLATFORM-SHELFMGR-6-NODE_STATE_CHANGE : 0/1/CPU0 A9K-MOD80-TR state:ROMMON 
RP/0/RSP1/CPU0:Nov  6 23:41:30.538 : ce_switch_srv[53]: %PLATFORM-CE_SWITCH-6-UPDN : Interface 1 (LC_Slot_1) is down 
RP/0/RSP1/CPU0:Nov  6 23:41:30.553 : ce_switch_srv[53]: %PLATFORM-CE_SWITCH-6-UPDN : Interface 0 (LC_Slot_0) is down 
RP/0/RSP1/CPU0:Nov  6 23:41:37.321 : canb-server[150]: %PLATFORM-CANB_SERVER-7-CBC_POST_RESET_NOTIFICATION : Node 0/0/CPU0, Power Cycle (0x05000000)  
RP/0/RSP1/CPU0:Nov  6 23:41:37.333 : canb-server[150]: %PLATFORM-CANB_SERVER-7-CBC_POST_RESET_NOTIFICATION : Node 0/1/CPU0, Power Cycle (0x05000000)  
RP/0/RSP1/CPU0:Nov  6 23:42:13.885 : ce_switch_srv[53]: %PLATFORM-CE_SWITCH-6-UPDN : Interface 1 (LC_Slot_1) is up 
RP/0/RSP1/CPU0:Nov  6 23:42:13.900 : ce_switch_srv[53]: %PLATFORM-CE_SWITCH-6-UPDN : Interface 0 (LC_Slot_0) is up 
RP/0/RSP1/CPU0:Nov  6 23:42:14.410 : shelfmgr[375]: %PLATFORM-SHELFMGR_HAL-6-BOOT_REQ_RECEIVED : Boot Request from 0/0/CPU0, RomMon Version: 2.0 
RP/0/RSP1/CPU0:Nov  6 23:42:14.451 : shelfmgr[375]: %PLATFORM-MBIMGR-7-IMAGE_VALIDATED : Remote location 0/0/CPU0: : MBI tftp:/disk0/asr9k-os-mbi-4.2.3/lc/mbiasr9k-lc.vm validated 
RP/0/RSP1/CPU0:Nov  6 23:42:14.452 : shelfmgr[375]: %PLATFORM-SHELFMGR-6-NODE_STATE_CHANGE : 0/0/CPU0 A9K-MOD80-TR state:MBI-BOOTING 
RP/0/RSP1/CPU0:Nov  6 23:42:14.555 : shelfmgr[375]: %PLATFORM-SHELFMGR_HAL-6-BOOT_REQ_RECEIVED : Boot Request from 0/1/CPU0, RomMon Version: 2.0 
RP/0/RSP1/CPU0:Nov  6 23:42:14.557 : shelfmgr[375]: %PLATFORM-SHELFMGR-6-NODE_STATE_CHANGE : 0/1/CPU0 A9K-MOD80-TR state:MBI-BOOTING 


yes, we've already downgrade by turboboot, its success but LC doesnt coming UP.


Best Regards,


Hopefully this will help to explain it a bit more: In 4.2.0 we introduced the PX image for the RSP440 (to support x86) and still had the old P image for the PPC based RSP2 (RSP4G and RSP8G). In 4.3.0 we merged P and PX into the PX image (confusing I know). So downgrading to an old pre-4.3.0 PX or P image is a different architecture, but upgrading is fine as it has the old architectures plus more.


I don't see the reload reason in here, just the CBC PRE RESET notification. Please open a TAC case to investigate the logs further and see why the card is not booting.




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