Contents

Introduction

Background Information

Problem

Solution

Related Information

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

- Cisco Technical Support & Downloads