Alcatel Carrier Internetworking Solutions omniswitch User Manual

Managing CMM Directory Content

CMM Files

OmniSwitch 6600 Family Switch Management Guide

page 4-9

CMM software redundancy is one of the switch’s most important fail over features. For CMM software 
redundancy, at least two fully-operational OmniSwitches must be linked together as a stack. In addition, 
the CMM software must be synchronized. (Refer to 

 for more information.)

When two OmniSwitches are running in a stack, one switch has the primary role and one switch has the 
secondary role at any given time. (The primary and secondary roles are determined by the switch number 
indicated on the LED on the front panel; the lowest number switch becomes the primary switch in the 
stack.) The primary switch manages the current switch operations while the secondary switch provides 
backup (also referred to as “fail over”).

Additional OmniSwitches in a stack are set to “idle” for the purposes of redundancy. For more informa-
tion on managing a stack of switches, see “Managing Stacks” in the OmniSwitch 6600 Family Hardware 
Users Guide.

Note. A redundant stacking cable is required to fully support redundancy.

The following scenarios demonstrate how the CMM software is propagated to other switches in a stack for 
the purposes of coherent redundancy. In the examples below W represents the working directory and C 
represents the certified directory.

The following diagram illustrates what occurs when a stack powers up. The stack displayed is a three 
switch stack.

This process occurs automatically when the switch boots. The working and certified directory relationship 
described above in 

 still apply to the primary CMM switch. 

W

C

W

C

W

C

1. Stack is pow-

ered up and boots 

from the certified 

directory.

2. The contents of 

the certified direc-

tory of the primary 

CMM switch are 

copied to the 

working directory 

of the secondary 

CMM switch. The 

working directory 

is then copied to 

the certified direc-

tory.

3. The contents of 

the certified direc-

tory of the pri-

mary CMM switch 

are copied to the 

working directory 

of additional 

switches. The 

working directory 

is then copied to 

the certified direc-

tory.

Switch #1

Switch #2

Switch #3