Cisco Systems 4500 About Supervisor Engine Redundancy

8-2
Software Configuration Guide—Release 15.0(2)SG
OL-23818-01
Chapter 8 Configuring Supervisor Engine Redundancy Using RPR and SSO
About Supervisor Engine Redundancy
About Supervisor Engine Redundancy
These sections describe supervisor engine redundancy:
• Overview, page 8-2
• RPR Operation, page 8-3
• SSO Operation, page 8-3
Overview
With supervisor engine redundancy enabled, if the active supervisor engine fails or if a manual
switchover is performed, the redundant supervisor engine becomes the active supervisor engine. The
redundant 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 redundant 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 8-13.
To minimize down time during software changes on the supervisor engine, load the new image on
the redundant 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 occurs 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 8-1 provides information about chassis and supervisor engine support for redundancy.
Table 8-1 Chassis and Supervisor Support
Chassis
(Product Number) Supported Supervisor Engines
Catalyst 4507R
(WS-C4507R) Supports redundant Supervisor Engine II-Plus (WS-X4013+), redundant Supervisor Engine II-Plus (WS-X4013+GE),
Supervisor Engine IV (WS-X4515), redundant Supervisor
Engine V (WS-X4516), and redundant Supervisor Engine V
(WS-X4516-10GE).
Catalyst 4510R
(WS-C4510R) Supports redundant Supervisor Engine V (WS-X4516) and redundant Supervisor Engine V (WS-X4516-10GE).