Availability Features; Management Module Redundancy - Alcatel OmniSwitch 6800 Series Hardware User's Manual

OmniSwitch 6800 Series

Availability Features

The switch provides a broad variety of availability features. Availability features are hardware- and
software-based safeguards that help prevent the loss of data flow in the unlikely event of a subsystem fail-
ure. In addition, some availability features allow users to maintain or replace hardware components with-
out powering off the switch or interrupting switch operations. Combined, these features provide added
resiliency and help ensure that the switch or virtual chassis is consistently available for day-to-day
network operations.
Hardware-related Availability features include:

Management Module Redundancy

•
Software Rollback
•
Backup Power Supplies
•
Hot Swapping
•
Hardware Monitoring
•
Management Module Redundancy
In stacked configurations, one OmniSwitch 6800 Series switch is designated as the primary "management
module" for the stack. Because the stack can be thought of as a virtual chassis, the role of this primary
management switch is to monitor and manage the functions of the stack.
Similar to chassis-based switches such as the OmniSwitch 7700 and Omniswitch 7800, the stack also
allows users to assign an additional switch as a secondary management module. As with the OS7700 and
OS7800, the stack's secondary switch immediately takes over management functions in the event of a
primary switch failure.
All other switches in the stack are considered idle, and act very much like Network Interface (NI)
modules, in that they provide Ethernet ports for 10/100/1000 traffic.
The stack provides support for all idle switches during primary-to-secondary failover. In other words, if
the stack's primary switch fails or goes offline for any reason, all idle switches will continue data trans-
mission during the secondary switch's takeover process.
Incoming Layer 2 packets will continue to be sent to the appropriate egress port during failover. Spanning
Tree will continue handling BPDUs received on the switch ports, as well as port link up and down states.
The Spanning Tree topology will not be disrupted.
Note. For detailed information on primary, secondary, and idle switches, as well as the failover process,
refer to Chapter 3, "Managing OmniSwitch 6800 Series Stacks."
OmniSwitch 6800 Series Hardware Users Guide July 2005
Availability Features
page 1-5