Allied Telesis AT-S63 - Manual (Page 36)

Chapter 1: Overview
36 Section I: Basic Operations
Active Configuration File
The parameter settings of the stack are stored in the active configuration
file in the master switch’s file system. In the file are the commands that
reestablish the current configuration of the ports and switches in the stack.
The file is used by the master switch whenever the stack performs the
discovery process, such as after a reset or a power cycle, or a change to a
stack’s composition.
The master switch does not automatically update the active configuration
file when a change is made to a parameter setting on a stack device.
Instead, you must manually initiate the update with the SAVE
CONFIGURATION command. In response to the command, the master
switch polls all of the devices in the stack for their current settings and
updates the active configuration file. Since changes to the parameter
settings that are not saved to the configuration file are discarded
whenever the stack performs the discovery process, you should always
perform the SAVE CONFIGURATION command after you have made
changes to parameter settings that you want the stack to retain.
If the switches of a stack have static module ID numbers, a backup copy of
the master switch’s active configuration file is stored in the file system in
the switch assigned module ID 2. The backup configuration file is updated
whenever the SAVE CONFIGURATION command is issued, and so is an
exact duplicate of the active configuration file on the master switch.
Under normal operating conditions, the backup configuration file remains
inactive. However, if the master switch stops operating or is removed from
the stack, the switch assigned module ID 2 assumes the role of the master
switch during the subsequent discovery process and configures the stack
devices with its backup copy of the configuration file. If the original master
switch resumes operations, it reassumes the master switch role after the
discovery process and configures the stack with the active configuration
file in its file system. The configuration file on the switch assigned module
ID 2 reverts to its backup status.
Beginning with Version 3.0.0 of the AT-S63 Management Software a
switch has two default configuration files. One file is for stand-alone
operation and the other for stack operation, specifically when it is the
master switch of a stack. A switch chooses the appropriate file during the
discovery process. If, during the process, the switch determines it is not
part of a stack, it uses its stand-alone configuration file to set its parameter
settings. If it is the master switch of a stack, it uses its stack configuration
file to set the parameter settings of all the devices. Finally, if the switch
detects that it is part of a stack, but is not the master switch, it ignores the
configuration files in its file system and waits to receive its settings from
the master switch.