[c-nsp] Wierd C3560 config changes

[Simon Lockhart]

All,

I've got a bunch of Cisco 3560-xxTS's deployed as edge switches. Of the most
recent batch, I've got just one switch which is showing odd behaviour, and
I'm wondering if anyone has seen this before.

The switch is running c3560-ipbasek9-mz.122-53.SE2

I'm monitoring the switch with rancid, and periodically, extra lines keep
appearing in the config. I'm not putting them there, and there's nothing
in the log around the time they appear...

Excerpts from what rancid spots:

  interface FastEthernet0/15                                                    
-  switchport trunk pruning vlan 2-960,969-1001                                 

+ no mac address-table learning vlan 4064-4067,4069                             

- no mac address-table learning vlan 4064-4067,4069                             

  interface FastEthernet0/16                                                    
+  switchport trunk pruning vlan 2-960,969-1001                                 

  interface FastEthernet0/16                                                    
-  switchport trunk pruning vlan 2-960,969-1001                                 

  interface FastEthernet0/16                                                    
+  switchport trunk pruning vlan 2-960,969-1001                                 

  interface FastEthernet0/16                                                    
-  switchport trunk pruning vlan 2-960,969-1001                                 

Occasionally, it's also crashing and rebooting...

System returned to ROM by address error at PC 0x1B6599C, address 0x0
System restarted at 06:31:09 BST Fri Jun 4 2010

I'd say it was a software bug, but it's only affecting one switch (out of about
20 running that specific IOS). Then again, I'm not convinced that it's a
hardware issue (why would hardware make likes appear/vanish from config?)

Any ideas?

Simon