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Brocade FastIron X Series Chassis Hardware Installation Guide
53-1001723-02
Hitless management support
5
What happens during a Hitless OS upgrade and Hitless switchover
The following steps describe the internal events that occur during a Layer 2 hitless OS upgrade and
hitless switchover.
1. The standby management module resets and reloads with the new software image in its flash
memory.
2. The Ethernet interfaces (if present) on the standby module become operational and start
carrying data traffic.
3. The active management module synchronizes the standby management module with all the
information required to take over the active role.
4. The Layer 2 control protocols on the standby management module converge. This process
takes approximately 70 seconds.
5. The standby management module takes over the active role.
6. The old active management module resets and reloads with the same software image running
on the current active management module.
7. The
FastIron
switch is now operating on the new software image. The management module
that was initially configured as the standby management module is now the active
management module and the management module that was initially configured as the active
management module is now the standby.
NOTE
The events described above occur internally and do not create or affect the external network
topology.
How a Hitless OS upgrade and Hitless switchover impacts system
functions
The following table highlights the implications of a hitless OS upgrade or hitless switchover to the
system’s major functions.
