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New Member

3745 keep booting into rommon


i have 3745 cisco router, it was operational for more than a 3 years.

now whenever i reboot it the boot gos into rommon, even i have a right configuration register value 0x2102 and the image on the internal flash is working .

to make it work i have to issue the boot command from the rommon and reload.

even the same command i executed from the config mode after reboot .

any help would be highly appricated .



Re: 3745 keep booting into rommon

1.Have you done any changes ?

2.Why you had rebooted it ?

3.attach sh run which will include boot-start-marker & booot-end-marker

New Member

Re: 3745 keep booting into rommon

hey thanks for the quick reply

i did no changes and i reboot it because it was not responding, here are that part of the sh run


version 12.3

no service pad

service timestamps debug datetime msec

service timestamps log datetime msec

service password-encryption


hostname MOCY





enable secret 5


network-clock-participate wic 0

network-clock-participate aim 0

no aaa new-model

ip subnet-zero

ip cef



nothing is defined between the boot start and end markers even i issued the boot command but after the reboot that command disappear .

Hall of Fame Super Silver

Re: 3745 keep booting into rommon


Perhaps you would also post the output of show version and of show flash. This might have some information that would help us to identify the issue.



New Member

Re: 3745 keep booting into rommon

here are the required show

MOCY#sh ver

Cisco Internetwork Operating System Software

IOS (tm) 3700 Software (C3745-ADVENTERPRISEK9-M), Version 12.3(26), RELEASE SOFTWARE (fc2)

Technical Support:

Copyright (c) 1986-2008 by cisco Systems, Inc.

Compiled Mon 17-Mar-08 17:42 by dchih

ROM: System Bootstrap, Version 12.2(8r)T2, RELEASE SOFTWARE (fc1)

RAK_MOCY uptime is 12 minutes

System returned to ROM by reload

System image file is "flash:c3745-adventerprisek9-mz.123-26.bin"

cisco 3745 (R7000) processor (revision 2.0) with 248832K/13312K bytes of memory.

Processor board ID JHY0835K3UY

R7000 CPU at 350MHz, Implementation 39, Rev 3.3, 256KB L2, 2048KB L3 Cache

Channelized E1, Version 1.0.

Bridging software.

X.25 software, Version 3.0.0.

SuperLAT software (copyright 1990 by Meridian Technology Corp).

TN3270 Emulation software.

Primary Rate ISDN software, Version 1.1.

2 FastEthernet/IEEE 802.3 interface(s)

4 Serial network interface(s)

1 ATM network interface(s)

1 Channelized E1/PRI port(s)

1 ATM/Voice AIM(s)

DRAM configuration is 64 bits wide with parity disabled.

151K bytes of non-volatile configuration memory.

31168K bytes of ATA System CompactFlash (Read/Write)

Configuration register is 0x2102

------------------ show flash: all ------------------

-#- --length-- -----date/time------ path

1 252 Mar 1 1993 00:05:38 +00:00 RAQ-Pool

2 24577560 Mar 1 1993 00:13:56 +00:00 c3745-adventerprisek9-mz.123-26.bin

7151616 bytes available (24584192 bytes used)

******** ATA Flash Card Geometry/Format Info ********


Number of Heads: 4

Number of Cylinders 487

Sectors per Cylinder 32

Sector Size 512

Total Sectors 62336


Number of FAT Sectors 31

Sectors Per Cluster 8

Number of Clusters 7748

Number of Data Sectors 62176

Base Root Sector 155

Base FAT Sector 93

Base Data Sector 187



Hall of Fame Super Silver

Re: 3745 keep booting into rommon


Thank you for the additional information. I agree that it looks like the router should boot ok and that the image looks ok. Since it did have a problem with booting I suggest that you try this:

config t

boot system flash:c3745-adventerprisek9-mz.123-26.bin


copy running-config startup-config

Give this a try and let us know if it helps the router to boot without problems.



New Member

Re: 3745 keep booting into rommon

Hi Rick

i tried that but after i reboot the

boot system flash:c3745-adventerprisek9-mz.123-26.bin

disappear from the configuration file and the router goes to rommon, do you think it is a hardware problem and in case which part you think is damaged and how can we make sure of that .

Hall of Fame Super Silver

Re: 3745 keep booting into rommon


After you have done the copy running-config startup-config, if you do a show startup-config do you see the boot system flash command in the config file?

It does begin to sound a bit more like this could be a hardware problem. Is this router covered under an active maintenance contract so that you could open a case with TAC? If so I would suggest that this might be the direction to go.



New Member

Re: 3745 keep booting into rommon

i will open a case with cisco TAC.

thanks a lot for your help

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