Document ID: 23240
Valuable time and resources are often wasted replacing hardware that actually functions properly. This document helps troubleshoot common hardware issues with Cisco 7100 series routers, and provides pointers for identifying whether or not the fault is in the hardware. This document does not cover any software-related failures except for those that are often mistaken as hardware issues.
Readers of this document should be knowledgeable of the following:
The information in this document is based on the software and hardware versions:
Cisco 7100 Series Router
All Cisco IOS® software releases that run on the 7100 Series Router
The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.
For more information on document conventions, see the Cisco Technical Tips Conventions.
Cisco 7100 Series Virtual Private Network (VPN) routers offer specific hardware configurations optimized for VPN applications and network topologies. These include the Cisco 7120 Series and the Cisco 7140 Series Routers. The Cisco 7120 Series comes in six different models, and the Cisco 7140 Series comes in five different models. The models in both series are defined by a Wide Area Network (WAN) interface. Cisco 7100 Series Routers include the following:
Cisco 7120 series—Provides one fixed WAN port, two fixed 10BaseT/100BaseTX Fast Ethernet ports, one modular port adapter slot, and one service module slot
Cisco 7140 series—Provides two fixed WAN ports, two fixed 10BaseT/100BaseTX Fast Ethernet LAN ports, one modular port adapter slot, and one service module slot
Refer to Cisco 7100 Series VPN Router Product Overview for more information and a detailed description of the 7100 platforms.
This section covers the most common symptoms resulting from a potential hardware issue seen on the 71XX.
The symptoms are organized into two sections:
Step-by-Step Troubleshooting: Booting Issues—This section lists the procedure to follow when a failure prevents the router from booting. This can result from a hardware failure (the procedure helps to identify which particular part, such as memory or modules), a configuration, or a software issue. For every symptom, appropriate actions are listed.
When a router is experiencing a booting issue, the only information to capture are the complete logs of messages that may be displayed on the console during the boot sequence.
Post-booting issues—These can be router crashes, router hangs, error messages on the console, packet drops, high CPU utilization, and memory allocation failures. The root cause in these situations is either hardware or software. The most important information to collect is:
Console logs and/or syslog information
The crashinfo file (if the router is crashing)
Output from the show tech-support command, in enable mode
The table below lists symptoms and troubleshooting guidelines for booting issues.
|Symptoms||Basic Troubleshooting||Advanced Troubleshooting|
|Power LED is OFF||Troubleshooting the Power Subsystem||n/a|
|Power LED is ON, fans not operating||Troubleshooting the Cooling Subsystem||n/a|
|Power LED is ON, Nothing appears on the console||
||Perform advanced troubleshooting using the internal diagnostic LEDs located on the motherboard|
|Power LED is ON, Hang after printing the "System Bootstrap" banner||
||Perform advanced troubleshooting using the diagnostic mode|
|Power LED is ON, The router boots in ROMMON||
If the 71xx is stuck in ROMmon mode, set the configuration
register to 0x2102 and reload the router as follows:
rommon 1 > confreg 0x2102 rommon 2 > resetIf the router remains stuck in ROMmon, the reason is most likely a corrupt Cisco IOS software image or faulty Flash card. See ROMmon Recovery Procedure.
|Power LED is ON, The router boots in BOOT mode||
If the router is stuck in Bootmode, identified by the
Router_name(boot)> prompt, check if the
configuration register is 0x2102 from the show
version output. If the configuration register shows a setting
other than 0x2102, do the following:
Router_name(boot)#configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router_name(boot)(config)#config-register 0x2102 Router_name(boot)(config)#end Router_name(boot)#reload System configuration has been modified. Save? [yes/no]: no Proceed with reload? [confirm]Do NOT save the running configuration before reloading (you would lose the parts of the configuration that are not understood by the boot mode software). If the value of the configuration register is 0x2102 and you are still booting into Bootmode, it may be a boot failure from the PCMCIA card.
|Power LED is ON, router is booting in a loop||
The router is booting correctly, but some interfaces are not available.
%PA-2-UNDEFPA: Undefined Port Adaptor type # in bay # %PA-3-DEACTIVATED: port adapter in bay [#] powered off.
|The modular port adapter or service module is not recognized by the software. Use the Software Advisor (registered customers only) to find which software version is supporting that port adapter.|
%PA-3-DEACTIVATED: port adapter in bay [#] powered off
|If this is the modular port adapter or service module, try to reseat it and/or move it to another router to determine if the fault is on the card or on the slot. If this is a fixed port adapter, replace the chassis.|
If the enable LED is ON, but you are still experiencing issues with an interface, then this is most likely not a hardware issue. Further troubleshooting needs to be done. Collect relevant error messages and then refer to the Error Message Decoder (registered customers only) .
Other Issues: Router crashes, router hangs, memory allocation failure, high CPU utilization, performance issue
If you are experiencing router crashes, router hangs, or console error messages, more specific troubleshooting needs to be done because these various issues can be the consequence of a hardware or software problem.
Memory allocation failures, high CPU utilization, and performance issues are usually software or configuration issues.
You can find detailed information on how to troubleshoot these issues at Troubleshooting Cisco 7100 Series Routers.
This is part of the Step-by-Step Troubleshooting, Booting Issue section.
The diagnostic LEDs located on the motherboard (see picture below) tell you which boot operation is actually being performed, and help to identify at which step the router is hanging.
The table below shows several steps in the boot process and the corresponding LED indication (1 = LED ON, 0 = LED OFF).
|Boot Operation||LED numbers: 3 2 1 0|
|Power On Reset||1 1 1 1|
|Initialize R4K regs||1 1 1 1|
|Initialize gt64120 regs||1 1 1 1|
|Set up L2 cache||0 0 1 1|
|Start checking first 64K of DIMM1||0 1 0 0|
|DIMM1 Failure||0 1 0 1|
|Finished 64K DIMM1 Test||0 1 1 1|
|Clear GT64120 timer cntrl reg||1 0 0 0|
|Failed clearing timer cntrl reg||1 0 0 1|
|Check GT64120 revision||1 0 1 0|
|Read NVRAM Config Reg||1 0 1 1|
|Initialize UART||1 1 0 0|
|Turn off all LEDs and Print Banner||0 0 0 0|
|All LEDs are ON||
|LEDs = 0100, 0101, 0110||
|LEDs = 1000, 1001, 1010||
|LEDs = 1011||
|LEDs = 1100||
|All LEDs are OFF||Go to Advanced troubleshooting using the diagnotic mode|
The router hangs after printing the System Bootstrap banner:
System Bootstrap, Version 12.0(19990324:032255) , DEVELOPMENT SOFTWARE Copyright (c) 1999 by cisco Systems, Inc.
The diagnostic mode is enabled using a specific setting of the configuration register. If the 71xx hangs after the bootstrap banner, you cannot configure anything on the 71xx as there is no prompt. To change the configuration register value, you must configure the diagnostic mode on the nonvolatile RAM (NVRAM) of a healthy 71xx, and then move this NVRAM into the appropriate 71xx.
The procedure to do this follows.
Enable the diagnostic mode on a healthy 71xx:
rommon 2 > confreg Configuration Summary enabled are: diagnostic mode load rom after netboot fails break/abort has effect console baud: 9600 boot: image specified by the boot system commands or default to: cisco2-C7100 do you wish to change the configuration? y/n [n]: y disable "diagnostic mode"? y/n [n]: enable "use net in IP bcast address"? y/n [n]: disable "load rom after netboot fails"? y/n [n]: enable "use all zero broadcast"? y/n [n]: disable "break/abort has effect"? y/n [n]: enable "ignore system config info"? y/n [n]: change console baud rate? y/n [n]: change the boot characteristics? y/n [n]: Configuration Summary enabled are: load rom after netboot fails break/abort has effect console baud: 9600 boot: image specified by the boot system commands or default to: cisco2-C7100 do you wish to change the configuration? y/n [n]: You must reset or power cycle for new config to take effect rommon 3 > reset System Bootstrap, Version 11.3(2)XA4, RELEASE SOFTWARE (fc1) Copyright (c) 1999 by cisco Systems, Inc.
Power off the router and remove the NVRAM. Look at the figure below to locate the NVRAM on the motherboard.
Place this NVRAM chip into the router under troubleshooting and switch ON the router.
Below is a sample output of the additional diagnostic messages that the diagnostic mode prints during the boot:
System Bootstrap, Version 12.0(19990324:032255) , DEVELOPMENT SOFTWARE Copyright (c) 1999 by cisco Systems, Inc. Testing lower main memory - data equals address Testing lower main memory - checkerboard Testing lower main memory - inverse checkerboard Clearing lower 16K memory for cache initialization Clearing bss Reading monitor variables from NVRAM Enabling interrupts Initializing TLB Initializing cache Initializing R7K L2/L3 caches R7K CPU Initializing required TLB entries Initializing PCI subsystem Initializing main memory Config SDRAM parity check Initializing shared memory Sizing NVRAM Initializing PCMCIA controller Exiting init C7100 platform with 65536 Kbytes of main memory
Depending on which diagnostic message the boot sequence is hanging, you can identify which part of the hardware may be the root cause of the booting issue.
The table below shows possible boot sequence hangs, and the related diagnostic.
|If the boot sequence is hanging here...||Diagnostic|
Testing lower main memory - data equals address Testing lower main memory - checkerboard Testing lower main memory - inverse checkerboard Clearing lower 16K memory for cache initialization Clearing bss
|Synchronous Dynamic RAM (SDRAM) failure. Reseat the memory. If the problem persists, replace the SDRAM.|
Initializing TLB Initializing cache Initializing R7K L2/L3 caches
|CPU or External Cache Failure. Replace the chassis or router.|
Initializing PCI subsystem
|PCI Failure - Remove the modular port adapter and service module. If the router boots correctly, try to test the cards in another router to determine if the fault comes from a card or the slot.|
Initializing main memory Config SDRAM parity check Initializing shared memory
|SDRAM Failure - Reseat the memory. If the problem persists, replace the SDRAM|
Initializing PCMCIA controller
|PCMCIA Controller - Check the PCMCIA card. Try a spare card from another router (see PCMCIA Filesystem Compatibility Matrix). If the problem persists, replace the motherboard.|
- Cisco 7100 Series VPN Router Product Overview
- Troubleshooting the Power Subsystem
- Troubleshooting the Cooling Subsystem
- ROMmon Recovery Procedure
- Standard Break Key Sequence Combinations During Password Recovery
- Troubleshooting Cisco 7100 Series Routers
- PCMCIA Filesystem Compatibility Matrix
- Cisco 7100 Documentation
- Cisco Router Field Notices
- Technical Support & Documentation - Cisco Systems
|Updated: Jul 07, 2005||Document ID: 23240|