Cisco Catalyst 4500 Series, Software Configuration Manual

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12-2
Catalyst 4500 Series Switch, Cisco IOS Software Configuration Guide - Cisco IOS XE 3.9.xE and IOS 15.2(5)Ex
Chapter 12 Configuring Supervisor Engine Redundancy Using RPR and SSO on Supervisor Engine 7-E, Supervisor
About Supervisor Engine Redundancy
About Supervisor Engine Redundancy
These sections describe supervisor engine redundancy:
•
Overview, page 12-2
• RPR Operation, page 12-2
•
SSO Operation, page 12-3
Overview
With supervisor engine redundancy enabled, if the active supervisor engine fails or if a manual
switchover is performed, the standby supervisor engine becomes the “new” active supervisor engine.
The standby supervisor engine has been automatically initialized with the startup configuration of the
active supervisor engine, shortening the switchover time (30 seconds or longer in RPR mode, depending
on the configuration; subsecond in SSO mode).
In addition to the reduced switchover time, supervisor engine redundancy supports the following:
• Online insertion and removal (OIR) of the supervisor engine.
Supervisor engine redundancy allows OIR of the redundant supervisor engine for maintenance.
When the redundant supervisor engine is inserted, the active supervisor engine detects its presence,
and the redundant supervisor engine boots into a partially-initialized state in RPR mode and a
fully-initialized state in SSO mode.
• Software upgrade. (See the “Performing a Software Upgrade” section on page 12-12 .)
To minimize down time during software changes on the supervisor engine, load the new image on
the standby supervisor engine, and conduct a switchover.
When power is first applied to a switch, the supervisor engine that boots first becomes the active
supervisor engine and remains active until a switchover occurs.
A switchover will occur when one or more of the following events take place:
• The active supervisor engine fails (due to either hardware or software function) or is removed.
•
A user forces a switchover.
• A user reloads the active supervisor engine.
Table 12-1 provides information about chassis and supervisor engine support for redundancy.
RPR Operation
RPR is supported in Cisco IOS-XE Release 3.1.0SG and later releases. When a standby supervisor
engine runs in RPR mode, it starts up in a partially-initialized state and is synchronized with the
persistent configuration of the active supervisor engine.
Table 12-1 Chassis and Supervisor Support
Supported Switches Supported Supervisor Engines
WS-C4507R-E, WS-C4510R-E,
WS-E, WS-E Supervisor Engine 7-E (WS-X45-SUP7-E),
Supervisor Engine 7L-E (WS-X45-SUP7L-E),
and Supervisor Engine 8-E (WS-X45-SUP8-E)