Smart Continuous Switching; Software Rollback - Alcatel-Lucent OmniSwitch 9800E Hardware User's Manual

OmniSwitch 9000E Series

Smart Continuous Switching

In redundant CMM configurations, the switch provides support for NIs during failover. In other words, if
the primary CMM fails or goes offline for any reason, NI modules will continue data transmission and
routing functions during the secondary CMM's takeover process. This Availability feature is referred to as
Smart Continuous Switching.
Incoming Layer 2 packets will continue to be sent to the appropriate egress port during failover. Known
routes will also be supported. (Note, however, that the NI cannot learn new routes without CMM support.
Any new route information will be ignored.) 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. Smart Continuous Switching is designed to maintain data flow only during CMM failover and is not
intended to support long-term data flow. If both the primary and secondary CMM modules go offline or
are removed from the chassis, switch operations (including all NI support) will be disabled.
For more information on CMM redundancy and the failover process, refer to
ment Module (CMM)."

Software Rollback

Software rollback (also referred to as image rollback) essentially allows the switch to return to a prior
"last known good" version of software in the event of a system software problem. The CMM controls soft-
ware rollback through its resilient directory structure design (i.e., /flash/working and /flash/certified).
For detailed information on the software rollback feature, as well as the switch's /flash/working and
/flash/certified directories, refer to the "Managing CMM Directory Contents" chapter in the Switch
Management Guide.
OmniSwitch 9000E Series Hardware Users Guide December 2008
Availability Features
Chapter 3, "Chassis Manage-
page 1-3