Guest

Cisco Catalyst 4000 Series Switches

Field Notice: Accessing Switch Console Using a Terminal or Modem Can Cause Full Reset and/or Loss of Connectivity to WS-X4232-L3


May 30, 2002


Products Affected

Product

Top Assembly

Printed Circuit Assembly

Comments

Part Number

Rev.

Part Number

Rev.

WS-X4232-L3

68-0830-07

-B0

73-4333-07

-A0

Catalyst 4000 E/FE/GE L3 Module, 2-GE(GBIC),32-10/100

WS-X4232-L3=

68-0830-07

-B0

73-4333-07

-A0

Catalyst 4000 E/FE/GE L3 Module, 2-GE(GBIC),32-10/100 (Spare)

Problem Description

In some cases when a console cable is attached to or removed from console port of the WS-X4232-L3 card, the device locks up, then power cycles, causing full reset and/or loss of connectivity to the L3 card.

Background

With the configuration-register setting at 0x2 the break sequence (break to ROMMON) is enabled for as long as the switch is running on Cisco IOS® software. With the configuration-register set to 0x2, sometimes when you attach and disconnect the console cable to the console port of a WS-X4232-L3 this sends a break signal to the router blade causing a break sequence or reset.

With the the configuration registers set to 0x2102 the break sequence (break to ROMMON) is only enabled in the first few moments of boot-up. With the configuration register set to 0x2102 connecting or disconnecting the console cable to the console port of a WS-X4232-L3 will not cause a break sequence or reset. For instructions on changing the configuration register setting please refer to Workaround/Solution section of this field notice.

Problem Symptoms

When the configuration register is set to 0x2, in some cases when a console cable is attached to or removed from console port of the WS-X4232-L3 card, the device locks up, then power cycles, causing full reset and/or loss of connectivity to the L3 card.

There is a chance (possibly caused by noise from the terminal) that theWS-X4322-L3 module can go to ROMMON, causing the entire L3-switch to fully reset and/or loss of connectivity to WS-X4232-L3, possibly causing a network outage.

To find out what the configuration register setting is, issue the show version command. Verify at the bottom that the Configuration register is set to 0x2

DIS-4006#show version

------------------ show version ------------------

Cisco Internetwork Operating System Software
IOS (tm) L3 Switch/Router Software (CAT4232-IN-M), Version 12.0(7)W5(15d) RELEA
SE SOFTWARE
Copyright (c) 1986-2000 by cisco Systems, Inc.
Compiled Mon 05-Jun-00 16:39 by integ
Image text-base: 0x60010928, data-base: 0x605C8000

ROM: System Bootstrap, Version 12.0(7)W5(15b) RELEASE SOFTWARE

DIS-4006 uptime is 45 minutes
System restarted by power-on at 19:14:19 UTC Tue May 7 2002
Running default software

cisco Cat4232 (R5000) processor with 57344K/8192K bytes of memory.
R5000 processor, Implementation 35, Revision 2.1
Last reset from power-on
1 FastEthernet/IEEE 802.3 interface(s)
4 Gigabit Ethernet/IEEE 802.3z interface(s)
123K bytes of non-volatile configuration memory.

16384K bytes of Flash internal SIMM (Sector size 256K).
Configuration register is 0x2   

Workaround/Solution

It is recommended that you change the configuration register to 0x2102. This will allow for the break sequence to only be enabled for the first 60 seconds of boot up.

The way to do this is:
DIS-4006#configure terminal
DIS-4006(config)#config-reg 0x2102
DIS-4006(config)#^Z
DIS-4006#show version 
!--- Verify at the bottom that it !--- says Configuration register is 0x2 (it will be 0x2102 at next reload). 

For More Information

If you require further assistance, or if you have any further questions regarding this field notice, please contact the Cisco Systems Technical Assistance Center (TAC) by one of the following methods:

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