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Software Configuration Guide—Release 12.2(20)EW
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Chapter 6 Configuring Supervisor Engine Redundancy on the Catalyst 4507R and 4510R Switches
Configuring Supervisor Engine Redundancy
• With supervisor engine redundancy enabled, the supervisor engines may run different releases of
Cisco IOS software if both releases are Cisco IOS Release 12.1(12c)EW or later.
• The Forwarding Information Base (FIB) tables are cleared on a switchover. As a result, routed traffic
is interrupted until route tables reconverge.
• Static IP routes are maintained across a switchover because they are configured from entries in the
configuration file.
• Information about dynamic states maintained on the active supervisor engine is not synchronized to
the standby supervisor engine and is lost on switchover. Dynamic state information (such as border
gateway protocol [BGP] session information) is lost at switchover.
• The Catalyst 4507R switch and the 4510R switches are the only Catalyst 4500 series switch that
support supervisor engine redundancy.
• The Catalyst 4510R switch supports the WS-X4516 supervisor engine only. The Catalyst 4507R
switch supports the other redundant supervisor engines (Supervisor Engine II-Plus and Supervisor
Engine IV and WS-X4516). Do not mix and match different supervisor models in a redundancy
configuration.
• The active and standby supervisor engines must be in slots 1 and 2.
• Both the active and standby supervisor engines must support redundancy (Supervisor Engine
II-Plus, Supervisor Engine IV, and Supervisor Engine V). Earlier versions are not supported.
• Each supervisor engine must have the resources to run the switch on its own, which means that each
supervisor engine has its own Flash device and console port connections.
• Make separate console connections to each supervisor engine. Do not connect a Y cable to the
console ports.
• You must set the configuration register in the startup-config to autoboot. (See the “Modifying the
Boot Field” section on page 3-21.)
• With redundancy enabled, the supervisor engines can run different releases of Cisco IOS software
provided both releases are Release 12.1(12c)EW or later.
Note There is no support for booting from the network.
If these requirements are met, the switch functions in RPR mode by default.
Configuring Supervisor Engine Redundancy
Supervisor engine redundancy is configured by default when a second supervisor engine is detected.
This example shows how to display the redundancy state:
Switch#show redundancy states
my state = 13 -ACTIVE
peer state = 4 -STANDBY COLD
Mode = Duplex
Unit = Primary
Unit ID = 1
Redundancy Mode (Operational) = RPR
Redundancy Mode (Configured) = RPR
Split Mode = Disabled
Manual Swact = Enabled
Communications = Up
