We help IT Professionals succeed at work.

We've partnered with Certified Experts, Carl Webster and Richard Faulkner, to bring you two Citrix podcasts. Learn about 2020 trends and get answers to your biggest Citrix questions!Listen Now


Cisco Router Reboots Randomly - Need Help ASAP

Medium Priority
Last Modified: 2013-11-29
I currently have a Cisco 2821 at a remote site that seems to reboot every 10 hours or so.  The problem either lies with the hardware or the software.  Here is the pertinent information (sho context) and (sho region):


cb_iup#sho context

System was restarted by bus error at PC 0x410B01AC, address 0x15A3C78B at 07:45:29 UTC Tue Oct 24 20
2800 Software (C2800NM-ADVSECURITYK9-M), Version 12.4(5), RELEASE SOFTWARE (fc3)
Technical Support: http://www.cisco.com/techsupport
Compiled Tue 01-Nov-05 00:52 by alnguyen
Image text-base: 0x400A1B78, data-base: 0x41C20000

Stack trace from system failure:
FP: 0x44039238, RA: 0x410B01AC
FP: 0x44039258, RA: 0x410ED72C
FP: 0x440393C8, RA: 0x410BBE44
FP: 0x44039488, RA: 0x410BD99C
FP: 0x440394B8, RA: 0x410C083C
FP: 0x440396A8, RA: 0x40EF50DC
FP: 0x440396F8, RA: 0x40EF3880
FP: 0x44039748, RA: 0x40EF3B50

Fault History Buffer:
2800 Software (C2800NM-ADVSECURITYK9-M), Version 12.4(5), RELEASE SOFTWARE (fc3)
Technical Support: http://www.cisco.com/techsupport
Compiled Tue 01-Nov-05 00:52 by alnguyen
Signal = 10, Code = 0x43470000, Uptime 03:32:02
$0 : 00000000, AT : 00000000, v0 : 00020000, v1 : 00120000
a0 : 15A3C78B, a1 : 450C72CC, a2 : 00000006, a3 : 3F695EAC
t0 : 00000000, t1 : 00000001, t2 : 00000006, t3 : 440395D0
t4 : 441B2B4C, t5 : 44039620, t6 : 4403961C, t7 : 44039618
s0 : 000005C4, s1 : 450C72CC, s2 : 441B2B4C, s3 : 3F695E98
s4 : 00000000, s5 : 4402C4CC, s6 : 000005C4, s7 : 00000000
t8 : 44039490, t9 : 00000000, k0 : 3040A801, k1 : A000F000
gp : 432D6460, sp : 44039238, s8 : 40081951, ra : 410ED72C
EPC : 410B01AC, SREG : 3400FF03, Cause : 00000010
Error EPC : BFC00BBC, BadVaddr : 15A3C78B
CacheErr : E0C6A6E3, DErrAddr0 : 050C7300,
                            DErrAddr1 : 04793960

cb_iup#sho region
Region Manager:

      Start         End     Size(b)  Class  Media  Name
 0x0F400000  0x0FFFFFFF    12582912  Iomem  R/W    iomem:(uncached_iomem_region)
 0x3F400000  0x3FFFFFFF    12582912  Iomem  R/W    iomem
 0x40000000  0x4F3FFFFF   255852544  Local  R/W    main
 0x4000F000  0x41C1FFFF    29429760  IText  R/O    main:text
 0x41C20000  0x432D005F    23789664  IData  R/W    main:data
 0x432D0060  0x436F035F     4326144  IBss   R/W    main:bss
 0x436F0360  0x4F3FFFFF   198245536  Local  R/W    main:heap
 0x80000000  0x8F3FFFFF   255852544  Local  R/W    main:(main_k0)
 0xA0000000  0xAF3FFFFF   255852544  Local  R/W    main:(main_k1)

Free Region Manager:

      Start         End     Size(b)  Class  Media  Name


It looks as though the the router is trying to address 0x15A3C78B which is well outside the memory regions shown by the router.  So it is possible it is an IOS issue.  I am fairly new at this and would like a 2nd opinion.  If we cannot identify the problem within the next two hours we will be ordering a new Cisco router to ensure uptime at this location.   Thanks in advance.
Watch Question

Les MooreSr. Systems Engineer
Top Expert 2008
Post result of "show flash:" or dir flash:
Looking for dated crashdump files.
If there are any, it is an indication of software bug.
>Version 12.4(5
This release has been pulled from distribution
"DEFERRAL: 12.4(5) Platform Images
Cisco engineering has identified at least one serious software issue with the release which you have selected. This issue may disrupt network traffic. "

Not the solution you were looking for? Getting a personalized solution is easy.

Ask the Experts


Here are the results.  

cb_iup#sho flash
-#- --length-- -----date/time------ path
1     14892052 Dec 15 2005 18:48:22 +00:00 c2800nm-ipbase-mz.124-3a.bin
2         1649 Dec 15 2005 18:56:14 +00:00 sdmconfig-28xx.cfg
3      4052480 Dec 15 2005 18:56:34 +00:00 sdm.tar
4       812032 Dec 15 2005 18:56:50 +00:00 es.tar
5      1007616 Dec 15 2005 18:57:06 +00:00 common.tar
6         1038 Dec 15 2005 18:57:18 +00:00 home.shtml
7       113152 Dec 15 2005 18:57:30 +00:00 home.tar
8       511939 Dec 15 2005 18:57:42 +00:00 128MB.sdf
9     19312988 Oct 23 2006 15:21:58 +00:00 c2800nm-advsecurityk9-mz.124-5.bin
10      217839 Oct 24 2006 04:11:48 +00:00 crashinfo_20061024-041149
11      195959 Oct 24 2006 07:45:28 +00:00 crashinfo_20061024-074529
12      207203 Oct 24 2006 14:43:10 +00:00 crashinfo_20061024-144311

22667264 bytes available (41349120 bytes used)

I had been running the 'ipbase' IOS, I updated to the 'advsecurity' IOS last night, then today changed the boot file back to 'ipbase'.  There was a large number of crashdump files (150+) occurring under 'ipbase', I deleted those, then updated to 12.4(5) and was still receiving crashdumps so I just recently reverted back to 'ipbase' so the crashdump files below are most likely from 12.4(5)
Les MooreSr. Systems Engineer
Top Expert 2008

Given the deferral notice, it looks like a serious bug in both versions. If you have Smartnet, you can send a crashinfo file to Cisco for analysis, but the fix will still be an updated IOS. I'd go ahead with the fix while waiting for the analysis.
Sr. Systems Engineer
Top Expert 2008
This is a candidate bug
Cisco's output interpreter spit this out:
  The failure was caused by a software defect.Note that this is a bus error crash
  and can also be hardware related.


Yes, I had seen both of those when I logged into our Cisco account and did some research.  In re-reading I don't believe it to be a hardware error because the faulty memory address shown in the error message would have to indicate a valid memory address within a valid addressable range shown in the 'sho region' command.  The address is outside those bounds.  We have a couple older versions of IOS software but unfortunately we don't have channel partner status currently and are unable to download a newer version.  It just bothers me that there were no errors with the original 'ipbase' IOS and it just started throwing errors without even a config change.  Could you imagine faulty T1's being able to affect a router as the T1's we have at the site are bouncing quite a bit as an issue separate from the IOS issue?
Les MooreSr. Systems Engineer
Top Expert 2008

I can't imaging a bouncing T1 causing this type issue. It could be part of the software bugs that cause the bounce before crashing.
It is indeed a software bug. As for why it didn't happen when you used ipbase could be because of numerous reasons. Every IOS when they branch out, the interface drivers, memory allocator and everything else on the peripheral side gets compiled again and again. A bug fix if contradicts with an existing code could cause this. Easy way would be to upgrade the IOS than to buy a router.

I have seen a situation where in a firewall connected to a Yamaha router, only in this scenario, only with a specific code, if a change is done on the vpn, the whole thing goes down. 2000 units of this!

Access more of Experts Exchange with a free account
Thanks for using Experts Exchange.

Create a free account to continue.

Limited access with a free account allows you to:

  • View three pieces of content (articles, solutions, posts, and videos)
  • Ask the experts questions (counted toward content limit)
  • Customize your dashboard and profile

*This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.


Please enter a first name

Please enter a last name

8+ characters (letters, numbers, and a symbol)

By clicking, you agree to the Terms of Use and Privacy Policy.