Table of Contents

Contacting Cisco or Your Reseller
Recovering a Lost Password

Changing the Configuration Register
Resetting the Router
Resetting the Password
Resetting the Configuration Register Value

Problem Solving

OK LED Diagnostics
Troubleshooting WICs and VICs
Troubleshooting the Power System
Troubleshooting ISDN

Troubleshooting

Use the information in this chapter to help isolate problems you might encounter with the router or to rule out the router as the source of the problem.

This chapter contains the following sections:

• Contacting Cisco or Your Reseller

• Recovering a Lost Password

• Problem Solving

Contacting Cisco or Your Reseller

If you cannot locate the source of a problem, contact your local reseller for advice. Before you call, you should have the following information ready:

• Chassis type and serial number

• Maintenance agreement or warranty information

• Cisco IOS release installed on your router

• Date you received the router

• Brief description of the problem

• Brief description of the steps you have taken to isolate the problem

• Output from the show tech-support command

Recovering a Lost Password

This section describes how to recover a lost enable or enable secret password. The process of recovering a password consists of the following major steps:

• Changing the Configuration Register

• Resetting the Router

• Resetting the Password (for lost enable secret passwords only)

• Resetting the Configuration Register Value

Changing the Configuration Register

Follow these steps to change the configuration register:

Step 1 Connect an ASCII terminal or a PC running a terminal-emulation program to the console port on the rear panel of the router. Refer to the section "Connecting a PC" in the "Installation" chapter.

Step 2 Configure the terminal to operate at 9600 baud, 8 data bits, no parity, and 1 stop bit.

Step 3 Reboot the router by pressing the power switch to the off position, and then to the on ( | ) position.

Step 4 At the user EXEC prompt (Router>), enter the show version command to display the existing configuration register value (shown in bold in this example output):

Step 5 Record the setting of the configuration register. It is usually 0x0.

Resetting the Router

Follow these steps to reset the router:

• If break is enabled, go to Step 2.

• If break is disabled, turn the router off, wait 5 seconds, and turn it on again. Within 60 seconds, press the Break key. The terminal displays the ROM monitor prompt. Go to Step 3.

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Note Some terminal keyboards have a key labeled Break. If your keyboard does not have a Break key, refer to the documentation that came with the terminal for instructions on how to send a break. To send a break in Windows HyperTerminal, enter Ctrl-Break.

---

Step 2 Send a break. The terminal displays the following prompt:

Step 3 Enter confreg 0x142 to reset the configuration register:

Step 4 Initialize the router by entering the reset command:

Step 7 Enter the enable command to enter privileged EXEC mode. Configuration changes can be made only in this mode.

Step 8 Enter the show startup-config command to display an enable password in the configuration file:

If you are recovering an enable password, skip the following "Resetting the Password" section, and complete the password recovery process by performing the steps in the next section, "Resetting the Configuration Register Value."

If you are recovering an enable secret password, you will not see the display in the show startup-config command output. Complete the password recovery process by performing the steps in the following "Resetting the Password" section.

Resetting the Password

Follow these steps to reset the password:

Step 1 Enter the configure terminal command to enter configuration mode:

Step 2 Enter the enable secret command to reset the enable secret password in the router:

Step 3 Enter the config-register command and the original configuration register value that you recorded in Step 5 in the "Changing the Configuration Register" section earlier in this chapter.

Step 4 Press Ctrl-Z to exit configuration mode.

Router(config)# Ctrl-Z

Step 5 Save your configuration changes:

Resetting the Configuration Register Value

Follow these steps once you have recovered or reconfigured a password:

Step 2 Enter the config-register command and the original configuration register value that you recorded in Step 5.

Step 3 Press Ctrl-Z to exit configuration mode:

Router(config)# Ctrl-Z
 

Step 4 Reboot the router, and enter the recovered password.

Problem Solving

The key to problem solving is to isolate the problem to a specific subsystem by comparing what the router is doing to what it should be doing.

• WICs and VICs---Refer to the LEDs on the cards and the LEDs on the router front panel to help identify a failure. For more information on WICs and VICs, refer to the Cisco WAN Interface Cards Hardware Installation Guide that comes with each card.

• Cables---Check all the external cables that connect the router to the network.

• Power system---Check the external power source, power cable, router power supply, and circuit breaker. Check for inadequate ventilation or air circulation that might cause overheating.

• ISDN configuration---Consider ISDN-specific hardware and software configurations (ISDN BRI WICs only).

OK LED Diagnostics

Use the front-panel OK LED to help determine any problems with the router. When the router first boots up, it performs a power-on self-test (POST). If the router detects a problem during the POST, the OK LED blinks in a different pattern (described in Table 3-1), depending on the problem. A pattern is a specific number of blinks that is repeated until the router is turned off. If the router experiences any of these problems, contact your Cisco reseller.

Troubleshooting WICs and VICs

Use the show diag command to help determine problems with a card.

Router#show diag
Slot 0:
C1750 1FE VE Mainboard port adapter, 7 ports
Port adapter is analyzed 
Port adapter insertion time unknown
EEPROM contents at hardware discovery:
Hardware revision 0.0 			Board revision UNKNOWN
Serial number 1314672220 Part number    00-0000-00
Test history 0x0 RMA number 00-00-00
0x20:01 C9 00 00 4E 5C 4E 5C 00 00 00 00 00 00 00 00
0x30:00 00 00 04 00 00 00 00 00 00 00 00 00 00 00 00
WIC Slot 0:
Serial 2A/S (12in1) WAN daughter card
Hardware revision 1.0   Board revision A0
Serial number 0007947084Part number 800-03182-01
Test history 0x00 RMA number 00-00-00
Connector type    PCI
EEPROM format version 1
EEPROM contents (hex):
0x20:  01 13 01 00 00 79 43 4C 50 0C 6E 01 00 00 00 00 
0x30:  50 00 00 00 98 04 17 17 FF FF FF FF FF FF FF FF 
WIC Slot 1:
Dual FXS Voice Interface Card WAN daughter card
Hardware revision 1.1   Board revision C0
Serial number 0009907586 Part number 800-02493-01
Test history 0x00 RMA number 00-00-00
Connector type    WAN Module
EEPROM format version 1
EEPROM contents (hex):
0x20:  01 0E 01 01 00 97 2D 82 50 09 BD 01 00 00 00 00 
0x30:  60 00 00 00 98 08 22 01 FF FF FF FF FF FF FF FF 
 

The show diag command displays similar information for each port available on the router.

Table 3-2 lists problems that could occur with the WICs and VICs and the possible solutions of these problems.

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Table3-2: Troubleshooting WICs and VICs

Symptom
Possible Solution(s)

 Router does not recognize the card.
Confirm that the Cisco IOS release installed in the router supports the WIC or VIC.

Make sure you have a Cisco IOS feature set that supports voice. The CiscoWAN Interface Cards Hardware Installation Guide lists the software requirements for each card.

Make sure that the card is correctly installed in the router. Refer to the "Installing WICs and VICs" section in the "Installation" chapter.



 Router recognizes the card(s), but the card port(s) do not initialize.
Make sure that the card is correctly installed in the router. Refer to the "Installing WICs and VICs" section in the "Installation" chapter.

Check the external cable connections to make sure they are secure.



 Router does not boot properly or continuously or intermittently reboots.
 Make sure that the WIC or VIC is correctly installed in the router. Refer to the "Installing WICs and VICs" section in the "Installation" chapter.

 Router does not boot or reset after the WIC or VIC is inserted.
 There might be a short. Turn off the router immediately.

 Router boots, but the console screen is frozen.
Make sure the console cable is securely connected to the router and to the PC or terminal.

Verify that the parameters for your terminal are set to the following:


9600 baud


8 data bits


No parity 


1 stop bit


no flow control



 Router powers on and boots only when a particular WIC or VIC is removed from the router.
Confirm that the Cisco IOS release installed in the router supports the WIC or VIC. The CiscoWAN Interface Cards Hardware Installation Guide lists the software requirements for each card.

The router might be overheating. Contact your Cisco reseller.



 Router powers on and boots only when a particular cable is disconnected.
 There might be a problem with the WIC or VIC cables. Consult your Cisco reseller for warranty information.

Troubleshooting the Power System

If the router external power supply fails, return it to your Cisco reseller. Table 3-3 lists symptoms and possible solutions of power problems.

Table 3-3: Troubleshooting the Power System

Symptom	Possible Solution(s)
Router shuts down after being on for a short time.	Make sure that the area in which the router is installed meets the environmental site requirements in the "Technical Specifications" appendix in this guide and in the "Site Requirements" section in the Regulatory Compliance and Safety Information for the Cisco 1600 and Cisco 1700 Routers document that came with your router. Make sure nothing is blocking the fan vent on top of the router. If the front-panel PWR LED is not on, the power supply has failed.
The router attempts to boot, but all LEDs remain off.	The power supply has failed. Return the router to your Cisco reseller.
The router is on, but the front-panel PWR LED is off.	The power supply has failed. Return the router to your Cisco reseller.
The front-panel PWR LED is on, the front-panel OK LED is off, and the router does not pass console or EIA data.	The power supply has failed. Return the router to your Cisco reseller.

Troubleshooting ISDN

Because ISDN uses many variables and supports many different configurations, it sometimes can cause problems for the router. This section describes problems related to the ISDN line that might occur.

• For routers with an ISDN S/T WIC, enter the clear interface command to terminate any active ISDN calls and to reset the ISDN BRI interface. Do this for each ISDN port installed in the router:

Router# clearinterfacebri0
Router# clearinterfacebri1
 

• For routers with an ISDN U WIC, use the clear controller command to terminate any active ISDN calls, to reset the ISDN BRI interface, and to reset the ISDN line between the router and the central office switch. Do this for each ISDN port installed in the router:

Router# clearcontrollerbri0
Router# clearcontrollerbri1
 

Table 3-4 lists troubleshooting methods for ISDN-specific problems that might occur.

Posted: Mon Aug 9 19:00:28 PDT 1999
Copyright 1989-1999©Cisco Systems Inc.