System information

Chapter 3 Initially Configuring the ATM Switch Router
Configuring Redundancy and Enhanced High System Availability (Catalyst 8540 MSR)
3-30
ATM Switch Router Software Configuration Guide
78-6277-03, Cisco IOS Release 12.0(13)W5(19)
Configuring Switch Fabric Enhanced High System Availability Operation
(Catalyst 8540 MSR)
Slots 5, 6, and 7 in the ATM switch router chassis can accommodate either two or three switch
processor cards, with a switching capacity of 10 Gbps each. The possible configurations are as follows:
• Two switch processors—20 Gbps non-EHSA switching fabric (no spare)
• Three switch processors—20 Gbps EHSA switching fabric (one spare)
When three switch processors are installed, two are active at any time, while the third runs in standby
mode. By default, switch processors 5 and 7 are active and switch processor 6 is the standby. To force
the standby switch processor to become active, use the redundancy preferred-switch-card-slots
command.
Caution Do not hot swap an active switch processor module before putting it in standby mode.
Removing an active switch processor breaks active connections and stops the flow of
traffic through the switch. Put an active switch in standby mode using the redundancy
preferred-switch-card-slots command before removing it from the chassis.
When a switchover to the standby switch processor occurs, the system resets and all connections are
lost. When the system comes up again, all PVCs and SVCs are reestablished automatically.
Configuring Preferred Switching Processors (Catalyst 8540 MSR)
To configure which two of the three switch processors are active and which runs in standby mode, use
the following privileged EXEC command on the primary route processor:
Example
In the following example, the preferred switch processors are configured to be in slots 5 and 7 with the
slot 6 switch processor running in standby mode:
Switch# redundancy preferred-switch-card-slots 5 7
The preferred switch cards selected are already active
Note The preferred switch card slot configuration reverts to the default configuration when the
switch is power cycled.
Command Purpose
redundancy preferred-switch-card-slots
{5 | 6 | 7} {5 | 6 | 7}
Configures the active and standby switch
processors.