Brocade FastIron X Series Chassis Hardware Installation Guide
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Hitless management support
5
NOTE
All traffic going through Ethernet interfaces (if present) on the management modules will be
interrupted during a hitless OS upgrade. This is because both management modules must be
reloaded with the new image. This applies to hitless OS upgrade only. It does not apply to hitless
switchover, which does not interrupt traffic going through Ethernet interfaces on the management
modules.
NOTE
Static and dynamic multi-slot trunks will flap during a hitless switchover if any of the trunk port
members are on the management module.
Syslog message for Hitless OS upgrade and Hitless switchover
The following Syslog message is generated as a result of a switchover during a hitless OS upgrade
or hitless switchover.
HITLESS-RELOAD COMPLETED – Mgmt Module in slot <slotnum> is now Active
Layer 2 Hitless switchover
Hitless switchover
is a CLI-driven switchover of the active and standby management modules
without interruption to switched traffic. In software releases that do not support hitless switchover,
a manual switchover impacts the data traffic for the duration of the switchover and requires data
flows to be relearned.
This feature can be used by a system administrator, for example, to perform maintenance on a
management module that has been functioning as the active management module. The Layer 2
functions and protocols supported by hitless switchover are:
Traffic Type
Impact
Layer 2 switched traffic, including
unicast and multicast
Layer 2 switched traffic is not impacted during a manual switchover. All
existing switched traffic flows continue uninterrupted. New switched flows
are not learned by the
FastIron
switch during the switchover process and
are flooded to the VLAN members in hardware. After the new active
management module becomes operational, new switched flows are
learned and forwarded accordingly. The Layer 2 control protocol states are
not interrupted during the switchover process.
Layer 3 routed traffic, including
unicast and multicast
Layer 3 routed traffic is briefly interrupted during the manual switchover
process. The traffic will converge to normalcy after the new active CPU
becomes operational.
Management traffic
All existing management sessions (SNMP, TELNET, HTTP, HTTPS, FTP, TFTP,
SSH etc.), are briefly interrupted during the switchover process. All such
sessions are terminated and can be re-established after the new active
CPU takes over.
Security features
All security features other than configured ACLs are not hitless. Configured
ACLs will continue to operate in a hitless manner, meaning the system will
continue to permit and deny traffic during the switchover process.
All other security features are briefly interrupted during the switchover
process and will return to normalcy after the new active management
module is operational.