Cisco 2600 Series Multiservice Platforms

Cisco 2600 and 3600 Stay in ROM Monitor After Second Software Failure

June 18, 1998

Products Affected

Cisco 2610, Cisco 2611, Cisco 3620, Cisco 3640

Problem Description

Cisco has discovered a problem with the Cisco 2600 and 3600 series routers. These routers will not load the Cisco IOS™ after a software failure, the router remains in the ROM Monitor (ROMMON). If there is a boot system flash statement in the configuration, then the Cisco 2600 or 3600 will reboot after one software failure, but after a second failure the router will stay in ROMMON. If this happens, manual intervention is required to reboot the router.

Bug Details

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You can configure the ROMMON to work around this problem. To enable the router to reload a Cisco IOS image following a second software failure, the following commands can be typed at the rommon > prompt:

rommon 1>MONRC=BOOT=flash:,n; 
       rommon 2>sync 
       rommon 3>reset 

where "n" is the number of retries desired (on a Cisco 3600 router, "flash:" may be replaced with "slot0:", or "slot1:" depending on the location of the Cisco IOS image to be booted). The "sync" is required to save the change, and the "reset" is required to have it take effect.

For example, if n=100 (as in "MONRC=BOOT=flash:,100;"), Cisco IOS will automatically reload after a software failure, for up to 100 failures. After the 101st failure, the router will drop to the ROMMON prompt as before. Setting "n" very high (1000, for instance) will effectively cause the router to always reload after a crash.

Note: Use of the commands above will override any Cisco IOS boot system commands in the configuration.

If at any time you wish to undo the above changes, type the following at the rommon > prompt:

rommon 1>unset MONRC 
       rommon 2>unset BOOT 
       rommon 3>sync 
       rommon 4>reset 


This problem is fixed in a new ROMMON. The ROMMON is a physical chip that must be replaced on the router motherboard. Table 1 lists the problem versions and the fixed versions of the ROMMON.

Table 1—ROMMON Versions


Problem Versions

Fixed Version

2600 Series



3600 Series

11.1(7)AX, 11.1(17)AA


The version of ROMMON is displayed in the Cisco IOS show version command:

Router>show version
     Cisco Internetwork Operating System Software 
     IOS (tm) C2600 Software (C2600-IS-M), Version 11.3(2)XA, PLATFORM SPECIFIC RELE 
     TAC:Home:SW:IOS:Specials for info 
     Copyright (c) 1986-1998 by cisco Systems, Inc.
     Compiled Tue 10-Mar-98 13:42 by rnapier
     Image text-base: 0x80008084, data-base: 0x807B695C

     ROM: System Bootstrap, Version 11.3(1)XA, PLATFORM SPECIFIC RELEASE SOFTWARE (f)
     ROM: C2600 Software (C2600-IS-M), Version 11.3(2)XA, PLATFORM SPECIFIC RELEASE  

     Router uptime is 1 minute
     System restarted by power-on
     System image file is "flash:c2600-is-mz.113-2.XA", booted via flash

     cisco 2610 (MPC860) processor (revision 0x200) with 27853K/4915K bytes of memor.
     Processor board ID FFFF (48B25A24)
     M860 processor: part number 0, mask 32
     Bridging software.
     X.25 software, Version 3.0.0.
     1 Ethernet/IEEE 802.3 interface(s)
     4 Low-speed serial(sync/async) network interface(s)
     32K bytes of non-volatile configuration memory.
     8192K bytes of processor board System flash (Read/Write)
     Configuration register is 0x2102

Requesting an Upgrade

ROMMON upgrades can be ordered from Cisco as shown in Table 2.

Table 2—ROMMON Upgrades


Product Number

2600 Series


3600 Series


For More Information

If you require further assistance, or if you have any further questions regarding this field notice, please contact the Cisco Systems Technical Assistance Center (TAC) by one of the following methods:

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