Boot Problems; Contacting The Cisco Technical Assistance Center - Cisco Catalyst 9404R Switch Hardware Installation Manual

Troubleshooting
Possible BAUD Mismatch Scenario 2
Description—When you started off, the BAUD environment variable, startup-configuration speed and console
port speed were all 9600. (The BAUD and startup configuration speeds have not been set explicitly). After
this, at some point you explicitly set the BAUD variable to 115200...
1. You lose console access immediately. Set the console port speed to 115200 to restore access.
2. Boot the image—Line console speed is initially retrieved from BAUD (115200). While booting, the
system parses the startup-configuration, but even though the configured speed is 9600, this is the value
that the system defaults to, and the "speed 9600" line is not actually present in startup-configuration. Since
the speed configuration is not present, it is not explicitly parsed and applied, so the speed retrieved from
BAUD previously (115200) is used.
In this state, the line console speed is set to 115200, matching BAUD, while the startup-configuration has
line console speed as default (9600). The system is useable since the speed was not changed to 9600, even
with the BAUD and startup-configuration mismatch. If you save running configuration to start-up
configuration, then BAUD and startup-config will be in sync with speeds explicitly set to 115200.

Boot Problems

The supervisor module operates in a continuous loop by default if you have not set the boot variable
MANUAL_BOOT in ROMMON mode. To boot manually, set MANUAL_BOOT=yes; to auto-boot, set
MANUAL_BOOT=no.
The supervisor module goes into ROMMON mode or fails to boot when the system image is either corrupt
or absent.
The supervisor module has an onboard system Flash memory (bootflash), which can easily hold multiple
system images. Therefore, have a backup image. In addition to the bootflash, the supervisor module supports
compact Flash in the usbflash0: device. The supervisor also provides for transfer via TFTP of the image from
ROMMON mode, which enables faster recovery of absent or corrupt images.
In addition to the above mentioned storage devices, you can install a hard disk, which is displayed as disk0:.
We recommend that you use this for general purpose file storage, similar to usbflash0:, but not to store system
images.

Contacting the Cisco Technical Assistance Center

If you are unable to solve a startup problem after using the troubleshooting suggestions in this chapter, contact
a Cisco TAC representative for assistance and further instructions.
Before you call, have the following information ready to help the Cisco TAC assist you as quickly as possible:
• Date you received the switch
• Chassis serial number
• Type of software and release number
• Maintenance agreement or warranty information
• Brief description of the problem
• Console captures related to your problem
Cisco Catalyst 9400 Series Switches Hardware Installation Guide
Boot Problems
115