Router Crash - ISR C921

[secretAlpaca]

Hello, this is probably off topic but a quick glance and i didn't see a better forum.

My ISR 921 running on 4G has been crashing on me, how can i fix it? 

Stack Trace: 

000035: *Dec 25 23:02:41.413: %LINK-3-UPDOWN: Interface Cellular0, changed state to up
000036: *Dec 25 23:02:41.413: %LINEPROTO-5-UPDOWN: Line protocol on Interface Tunnel0, changed state to up
000037: *Dec 25 23:02:42.413: %LINEPROTO-5-UPDOWN: Line protocol on Interface Cellular0, changed state to up

23:04:43 UTC Sat Dec 25 2021: Unexpected exception to CPU: vector D, PC = 0x45AB85

-Traceback= 45AB85 45BCA7 45BB33 45626F 40E220 40C653 2777A02 275A7B0 275A4C0 2D9EA5 2E0A8B 2D8E16 2D882D 2D8527

CPU Register Context:
EAX = 0x00000002 ECX = 0x137CF808 EDX = 0x1137679C EBX = 0x00000000
ESP = 0x1001F244 EBP = 0x1001F28C ESI = 0x00000000 EDI = 0x00000000
EIP = 0x0045AB85 PS = 0x00010246 CS = 0x00000008 SS = 0x00000010
DS = 0x00000010 ES = 0x00000010 FS = 0x00000010 GS = 0x00000010

Writing crashinfo to flash:crashinfo_20211225-230443-UTC
No warm reboot Storage
Caught Exception Signal : A

show ver:

rt-edge-blm1 uptime is 4 minutes
System returned to ROM by bus error at PC 0x45AB85 at 23:04:43 UTC Sat Dec 25 2021
System image file is "flash:c900-universalk9-mz.SPA.158-3.M2.bin"
Last reload type: Normal Reload
Last reload reason: bus error at PC 0x45AB85

This is the first day it's crashing and it was after a major config change, can it have something to do with it? 

Thanks in advance.

[Leo Laohoo]

---

@secretAlpaca wrote:

Writing crashinfo to flash:crashinfo_20211225-230443-UTC

---

I want to see this file.  

Upgrade the IOS.  15.8(3)M2 is very old (release date 04 April 2019).

[secretAlpaca]

Hello,

Here is the huge crash log: https://pastebin.com/4YGeAzQ4

I bought the router through a network service provider and im still waiting for access to downloads for the product, so I can't update it as of now.

[Leo Laohoo]

---

@secretAlpaca wrote:

Pid 158: Process "IP Input" stack 0x10797268 savedsp 0x1079CFC4

---

Raise a Cisco TAC Case and get them to confirm if this is CSCvm94891.

[Georg Pauwen]

Hello,

what was the major configuration change ?

Post the current running config...

[secretAlpaca]

.

[secretAlpaca]

I bought the router new and it was just doing a simle cel 4g lte to a lan port, now i've mixed things a bit and it is serving a tunnel back to the datacenter to monitor snmp and obtain ip addresses from the dc, but I've only established the tunnel so far, i also added some ntp and syslog servers that aren't reachable as of now, could that have done it?

Config is here: https://pastebin.com/kFEx9XSc

[Richard Burts]

Thanks for the additional information. It is helpful to know that the router has been repurposed. I believe that it is pretty certain that some config change (perhaps one, perhaps several) caused the crashing problem. It might be possible to experiment with removing some of the config changes and see if you can identify the change(s) that cause this. But it would be quite difficult, and I believe not at all worth the effort. The solution is to obtain a different version of software. If you need to work through the service provider to get the software then this will delay your deployment of the router. I do not see any alternative that would be practical.

[marce1000]

 - Upgrade to an advisory release :

              https://software.cisco.com/download/home/282977114/type/280805680/release/15.7.3M9

 M.

[Richard Burts]

I would point out that the posted output does show that there was a "traceback". Traceback is always an indication of a software problem. If the router was running fine, a config change was made, and the problem started, it is pretty clear that the config change was the precipitating event. If you roll back the config change it is likely that the router would continue to work. If the config change is something that you need then a software upgrade is required.