Troubleshooting guide

112 Advanced System Diagnostics and Troubleshooting Guide
Limited Operation Mode and Minimal Operation Mode
Triggering Limited Operation Mode
On a BlackDiamond system with a single MSM, if a diagnostics test detects errors or if the POST fails,
the system goes into limited operation mode. Similarly, on a Summit or Alpine system, if a diagnostics
test detects errors, the Summit or Alpine switch will go into limited operation mode. When a failure
occurs, the system retains an error code.
In limited operation mode, you must use the clear log diag-status command to clear the hardware
error code so that the module—in the case of a BlackDiamond system, or the switch—in the case of an
Alpine or Summit system, can be brought up after the next reboot.
Bringing a Switch Out of Limited Operation Mode
To bring a switch out of limited operation mode, perform these steps:
1 Begin collecting background information that might help isolate the causes of the problem and
contact Extreme Networks technical support and notify them about the problem.
a Note any recent hardware or configuration changes.
b Create a detailed description of all the known symptoms.
c Capture the output from the show log command.
d Capture the output from the show diagnostics command.
e On a sheet of paper, write down the state of all LEDs on the switch.
2 Use the clear log diag-status command to clear the hardware error codes.
3 Use the reboot command to reboot the system.
4 Use the show tech CLI command to collect system information.
5 Send all of the information about the problem to Extreme Networks technical support.
Minimal Operation Mode
If the system reboots due to a failure that persists after the reboot, the system will reboot again when it
detects the failure again, and will continue that behavior across an endless cycle of reboots—referred to
as a reboot loop.
The ExtremeWare reboot loop protection feature provides a mechanism to detect a reboot loop and
force the system into minimal operation mode. In minimal mode, only the CPU, NVRAM, management
port, a minimal set of system tasks, and a minimal subset of CLI commands are active.
Triggering Minimal Operation Mode
To protect against reboot loops, you can configure reboot loop protection using the command:
configure reboot-loop-protection threshold <time-interval> <count>
If the switch reboots the specified number of times (<count>) within the specified time interval
(
<time-interval>), the switch stops rebooting and comes up in minimal operation mode.
For more information on the use of this command, see “Configuring Reboot Loop Protection” on
page 43.