Troubleshooting guide

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ATM and Layer 3 Switch Router Troubleshooting Guide
OL-1969-01
Chapter 3 Initial Troubleshooting
Troubleshooting Processor Redundancy and EHSA (Catalyst 8540 CSR and Catalyst 8540 MSR)
Route Processor Redundant Operation (Catalyst 8540 CSR and
Catalyst 8540 MSR)
The Catalyst 8540 MSR and Catalyst 8540 CSR supports fault tolerance by allowing a secondary route
processor to take over if the primary fails. This secondary, or redundant, route processor runs in standby
mode. In standby mode, the secondary route processor is partially booted with the Cisco IOS software;
however, no configuration is loaded.
At the time of a switchover, the secondary route processor takes over as primary and loads the
configuration as follows:
• If the running configurations on the primary and secondary route processors match, the new primary
uses the running configuration file
• If the running configurations on the primary and secondary route processors do not match, the new
primary uses the last saved configuration file in its nonvolatile random-access memory (NVRAM)
(not the NVRAM of the former primary)
The former primary then becomes the secondary route processor.
Note If the secondary route processor is unavailable, a major alarm is reported. Use the show
facility-alarm status command to display the redundancy alarm status.
For detailed redundant route processor configuration information, refer to the “Initially Configuring the
ATM Switch Router” chapter in the ATM Switch Router Software Configuration Guide.
Troubleshooting Route Processor Redundancy (Catalyst 8540 CSR and
Catalyst 8540 MSR)
For redundant route processors to function correctly, your switch router’s route processors must meet all
of the following requirements:
• Route processors must have identical hardware configurations
• ROMMON must be version 12.0(4.6)W5(13) or later
• Both route processors must have identical releases of IOS software
A common error you may encounter is the incompatibility of hardware modules and the IOS software
version needed to perform a particular function. Check the Hardware and Software Compatibility Matrix
document, available on-line, to confirm that you are using IOS software that supports the various
hardware components installed in your switch router.