Introduction
This document describes how to recover the Cisco 4000 series ISR from ROMMON when configured with Cisco IOS®-XE release of an incorrect platform.
Background Information
This document describe step-by-step process on how to troubleshoot and recover Cisco 4000 series ISR (Integrated Services Router) from ROMMON or infinite boot loop if configured with Cisco IOS-XE release of incorrect platform. At times Cisco 4000 series ISR gets stuck in ROMMON or continuous boot loop.
Problem
Cisco 4400 and Cisco 4300 series routers have Cisco IOS-XE images looks very similar in case you configured the Cisco 4400 with Cisco IOS-XE release for Cisco 4300 or vice-versa. The router does not bootup completely, rather, it gets stuck in ROMMON.
This is a Cisco 4400 configured with an Cisco IOS-XE release of Cisco 4300:
Cisco ISR4431/K9 (1RU) processor with 1665895K/6147K bytes of memory.
Processor board ID XXXXXXXXXX
4 Gigabit Ethernet interfaces
32768K bytes of non-volatile configuration memory.
4194304K bytes of physical memory.
7057407K bytes of flash memory at bootflash:.
4013055K bytes of USB flash at usb1
ROUTER#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
ROUTER(config)#boot system flash bootflash:isr4300-universalk9.3.13.01.S.154-3.S1-ext.SPA.bin
ROUTER(config)#end
ROUTER#
ROUTER#show running-config | include boot
boot-start-marker
boot system flash bootflash:isr4300-universalk9.03.13.01.S.154-3.S1-ext.SPA.bin
boot-end-marker
If you reload this router, the router gets stuck in ROMMON mode with this message on boot-up:
%IOSXEBOOT-1-INVALID_IMAGE: (RP/0): Booting an invalid ISR4300 image - Reloading system.
The methods to bring router up with correct Cisco IOS-XE image do not work.
1. Try to bring router up with an USB Flash:
rommon 1 > boot usb1:isr4400-universalk9.03.15.01.S.155-2.S1-std.SPA.bin
Please reset before you reboot:
rommon 2 > reset
2. Try to ignore startup-config and bring router up without startup configuration:
rommon 3 > confreg 0x2142
You must reset or power cycle for the new config to take effect:
rommon 4 > boot usb1:isr4400-universalk9.03.15.01.S.155-2.S1-std.SPA.bin
You need to reset before you boot:
rommon 5 > reset
3. Try to bring router up from traditional bootflash file system:
rommon 6 > boot bootflash:isr4400-universalk9.03.15.01.S.155-2.S1-std.SPA.bin
Reset before you continue:
rommon 7 > reset
4. In some cases, the internal bootflash file system does not recognized by router:
rommon 8 > dir bootflash:
Reset before you continue:
rommon 9 > reset
Solution
This is the correct process to recover this infinite boot loop issue:
1. Break router into ROMMON mode with break sequence while you boot-up:
rommon 1 >
2. Change the config-register vlaue to 0x0 to ignore the boot variable configured in startup config:
rommon 1 > confreg 0x0
You must reset or power cycle for new config to take effect:
rommon 2 > reset
3. This brings the router into ROMMON mode again. Then change the config-register value to 0x2102:
rommon 3 > confreg 0x2102
4. Now you need to configure the correct boot variable from ROMMON:
rommon 4 > boot bootflash:isr4400-universalk9.03.15.01.S.155-2.S1-std.SPA.bin
Once router is up, you can delete the incorrect boot variable and confgure the correct Cisco IOS-XE release:
ROUTER(config)#no boot system flash bootflash:isr4300-universalk9.03.13.01.S.154-3.S1-ext.SPA.bin
ROUTER(config)#boot system flash bootflash:isr4400-universalk9.03.15.01.S.155-2.S1-std.SPA.bin
5. Save the changes:
ROUTER#write memory
For the password recovery guide for the Cisco 4000 Series Integrated Services Router, refer to Troubleshoot Guide for the Cisco 4000 Series Integrated Services Router.
Related Information
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