Quick Reference Guide

Troubleshooting | 277
Recovering from a Lost Password
The default CLI user, admin, has read/write access, with no password until you create one. Once created,
the only way to recover from a lost admin password is to reload the switch using factory defaults. See
Restoring the System to the Factory Default Configuration on page 58.
Alternatively, if the user is not admin, then you can assign a new password to the user. See Creating a User
and Password on page 36.
Recovering from Switch Stack Problems
If a master switch (management unit of a stack) fails, or if a newly added switch in a stack is not
recognized, the stacking algorithm in each S-Series switch sets the switch to automatically negotiate with
connected units to determine the stack manager and unit numbering. See Management Unit Selection
Algorithm on page 85 and Unit Number Assignment on page 86. You can manually intervene by
selectively unplugging and reconnecting switches, and by manipulating the values that appear in the
algorithm. See Adding a Switch to a Stack on page 89.
When a switch cannot transmit packets to a destination stack member, you may see console messages
similar to the following:
Figure 18-262. Console Message: communication timeout
ATP, in the screen capture, above, refers to the SFTOS task used for stack member communication. These
messages point to a communication problem with a stack member assigned an ID of d8:2e, which is
derived from the last two digits of the MAC address of the switch. This condition may result from the
following:
• Bad stacking cables or hardware components (connectors, bus...)
• Improperly connected cable
• Improperly seated module
An RPC timeout message like the following indicates a communication problem between the management
unit and the member switch with the MAC address of 0:1:e8:d5:e6:20. The communication problem in this
case was caused by the stack cable.
STACK: communication timeout to d8:2e
ATP: TX timeout, seq 24554. cli 778. to 1 tx cnt 21.
RPC - Timeout to CPU: 0:1:e8:d5:e6:20.