Cisco Systems WSC4507RE96V Understanding Supervisor Engine Redundancy, Chassis Product Number

Chapter 6 Configuring Supervisor Engine Redundancy on the Catalyst 4507R and 4510R Switches

Understanding Supervisor Engine Redundancy

The standby supervisor engine runs in RPR mode. When RPR mode is used, the standby supervisor engine partially boots and keeps synchronized copies of the active configuration, which shortens the time needed to bring up the standby supervisor engine and have it start handling traffic from 1.5 minutes (for a cold boot on the standby) to 30 seconds (to finish the boot and reestablish links).

In addition to the reduced switchover time, supervisor engine redundancy supports the following:

•Online insertion and removal (OIR) of the standby supervisor engine.

•Software upgrade. (See the “Performing a Software Upgrade” section on page 6-6.)

•Auto-startup and bootvar synchronization.

•Hardware signals that detect and decide the active or standby status of supervisor engine.

•Automatic switchover to the standby supervisor engine if the active supervisor engine ever fails.

When the switch is powered on, the two supervisor engines determine which will serve as the primary and which will be the standby. Usually, the supervisor engine that boots first, either in slot 1 or 2, becomes the active supervisor engine.

A switchover will occur when one or more of the following events take place:

•The active supervisor engine fails or is removed.

•A user forces a switchover.

•A user reloads the active supervisor engine.

•A core dump occurs.

Note In a switchover, there is a disruption of traffic because some address states are lost and then restored after they are dynamically redetermined.

Table 6-1lists the chassis and supervisor support for redundancy.

Table 6-1 Chassis and Supervisor Support

Chassis

(Product Number)

Supported Supervisor Engines

Catalyst 4507R	Supports redundant Supervisor Engine II-Plus and
(WS-C4507R)	(WS-X4013+) and redundant Supervisor Engine V, Supervisor
	Engine IV (WS-X4515)
Catalyst 4510R	Supports redundant Supervisor Engine VSupervisor Engine V,
(WS-C4510R)	(WS-X4516)

Understanding Supervisor Engine Redundancy

These sections describe supervisor engine redundancy:

•Operation, page 6-3

•Supervisor Engine Synchronization, page 6-3

	Software Configuration Guide—Release 12.2(20)EW
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