[c-nsp] Router rebooting due to software crash.

[Joseph Mays]

We have a cisco 3600 that has rebooted twice in the last two hours, both times due to a software crash that shows the same memory address. I checked "show mem" and nothing is listed as operating that address, at least not right now. This router has been in operation a long time and has not had these problems previously. Nothing has changed in the config on the router in the last several months, at least.

gw1.dist#show ver
Cisco Internetwork Operating System Software
IOS (tm) 3600 Software (C3640-IS-M), Version 12.3(6), RELEASE SOFTWARE (fc3)
Copyright (c) 1986-2004 by cisco Systems, Inc.
Compiled Wed 11-Feb-04 18:02 by kellythw
Image text-base: 0x60008B00, data-base: 0x61B9C000

ROM: System Bootstrap, Version 11.1(20)AA2, EARLY DEPLOYMENT RELEASE SOFTWARE (fc1)

gw1.dist uptime is 9 minutes
System returned to ROM by error - a Software forced crash, PC 0x604F0D20 at 14:22:26 EDT Mon Aug 5 2013
System restarted at 14:24:08 EDT Mon Aug 5 2013
System image file is "flash:c3640-is-mz.123-6.bin"

cisco 3640 (R4700) processor (revision 0x00) with 124928K/6144K bytes of memory.
Processor board ID 11876053
R4700 CPU at 100MHz, Implementation 33, Rev 1.0
Bridging software.
X.25 software, Version 3.0.0.
SuperLAT software (copyright 1990 by Meridian Technology Corp).
2 FastEthernet/IEEE 802.3 interface(s)
3 Serial network interface(s)
1 Subrate T3/E3 ports(s)
DRAM configuration is 64 bits wide with parity disabled.
125K bytes of non-volatile configuration memory.
24576K bytes of processor board System flash (Read/Write)

Configuration register is 0x2102

I checked "show mem" and this address doesn't show up currently. Any clues on how to isolate what is causing this?