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New Member

cisco 837 crash (IOS 12.2(8)YN aka 12.2(11.2u)T)

I'm a relative newbie to cisco hardware, and I'm having trouble at a

pretty early hurdle. Having purchased an 837 for uk adsl access I

have basic nat'd access working.

However, one of my requirements was for an internal DNS server

(serving authorative zones).

I have a /29 subnet. I've (attempted) to 1-to-1 IP address map an

external IP to the internal DNS server:

ip nat inside source static network pub.lic.add.ress /32

(substituting the obvious IPs)

adding the additional access-lists to enable access:

access-list 111 permit udp any host pub.lic.add.ress eq domain

access-list 111 permit tcp any host pub.lic.add.ress eq domain

TCP rule works ok, (checked with telnet). However the instant a (udp)

DNS request is made from the internet (using 'dig' or 'nslookup'), the

router resets. This happens immediatly the request is made, and under

no other circumstances.

I would be _really_ grateful if anybody could help me here. I'm

completely lost for answers.

Crash log:

Unexpected exception to CPU vector 1200, PC = 8070AE0C

-Traceback= 8070AE0C 806EFC70 806F039C 802A2938 802A1688 802A1874

802A19D8 8014F9B8

=== Flushing messages (01:44:49 UTC Mon Mar 1 1993) ===

Queued messages:

Data TLB Miss Exception (0x1200)!

CPU Register Context:

VEC = 1200 PC = 8070AE0C MSR = 9032 CR = 33000035

LR = 8070ACF8 CTR = 80703DE4 XER = 8000D67E

R0 = 0 R1 = 810C7258 R2 = 80D90000 R3 = 0

R4 = FCF4 R5 = 3D75 R6 = 0 R7 = 0

R8 = 0 R9 = 80D90000 R10 = FFFFFFFF R11 = 0

R12 = 33000038 R13 = FFF32D6C R14 = 0 R15 = 0

R16 = 0 R17 = 0 R18 = 0 R19 = 0

R20 = 5105A313 R21 = C0A8030B R22 = 5105A313 R23 = D99B3D75

R24 = 0 R25 = 0 R26 = 810C7350 R27 = 1D49E1C

R28 = 81354454 R29 = 1D49E1C R30 = 81354454 R31 = 810833C4

Stack trace:

PC = 8070AE0C, SP = 810C7258

Frame 00: SP = 810C7258 RA = 806EFC70

Frame 01: SP = 810C72D0 RA = 806F039C

Frame 02: SP = 810C72F0 RA = 802A2938

Frame 03: SP = 810C7338 RA = 802A1688

Frame 04: SP = 810C7380 RA = 802A1874

Frame 05: SP = 810C73D0 RA = 802A19D8

Frame 06: SP = 810C73F0 RA = 8014F9B8

.rame 07: SP = 810C7410 RA = 0

*** System received a SegV exception ***

signal= 0xb, code= 0x1200, context= 0x80df7768

PC = 0x8070ae0c, Vector = 0x1200, SP = 0x810c7258


Tom Seeley

(frustrated) Cisco 837 owner.


Re: cisco 837 crash (IOS 12.2(8)YN aka 12.2(11.2u)T)


SegV exceptions usually occur due to bugs, or when a process tries to access an invalid memory addrfess, or write to an invalid memory address,.

Give a " show stacks" command and paste the output either here, for further troubleshooting, or you can use Output Interpreter t display potential issues and fixes. Output Interpreter will tell you if there are any matching bugs, related to this issue.

If its not yet getting solved, the best thing to do would be to copy outputs of "show tech" and perhaps a crashinfo file (generated the next time a crash occurs) and contact Cisco TAC.

New Member

Re: cisco 837 crash (IOS 12.2(8)YN aka 12.2(11.2u)T)

Its crashing every few minutes now, nothings changed though, so I don't see what could be causing the increased frequency of restarts:

myrouter>show stacks

Minimum process stacks:

Free/Size Name

5444/6000 PostOfficeNet

7232/12000 Init

Interrupt level stacks:

Level Called Unused/Size Name

1 0 9000/9000 ADSL Dying Gasp Interrupt

4 56726 7484/9000 MPC860 CPM INTERRUPT

5 646 8556/9000 ADSL Ctrl Interrupt

7 47230 8900/9000 TIMER INTERRUPT

System was restarted by error - a SIGTRAP exception, PC 0x8014AB90

C837 Software (C837-K9O3Y6-M), Version 12.2(8)YN, EARLY DEPLOYMENT RELEASE SOFT)

Synched to technology version 12.2(11.2u)T

TAC Support:

Compiled Wed 30-Oct-02 15:35 by ealyon (current version)

Image text-base: 0x800131D8, data-base: 0x8091FE68

Stack trace from system failure:

FP: 0x810C71B0, RA: 0x8014AB88

FP: 0x810C71C8, RA: 0x80130210

FP: 0x810C71E8, RA: 0x8012D220

FP: 0x810C7210, RA: 0x806FE5D0

FP: 0x810C7218, RA: 0x80707430

FP: 0x810C7258, RA: 0x8070A734

FP: 0x810C72D0, RA: 0x806EFC70

FP: 0x810C72F0, RA: 0x806F039C

Unfortunately I don't have a CCO account with which to register my problem, or run the Output Interpreter.



Re: cisco 837 crash (IOS 12.2(8)YN aka 12.2(11.2u)T)


The stack decoder provides the following output.

Error : No matching bug was found, probably a new bug

The stack trace decoded symbols are:








This crash, could be result of a new bug.So you would probably want to open a case with cisco, or your reseller, (you can contact cisco TAC if you have smartnet, or if you have purchased maintenance from reseller, then you need to contact their TAC, Make sure you have the contract number with them, before you call).

Hope that helps!

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