Specifying the master CPU and the standby-to-master delay

About this task

Configure the standby-to-master delay to set the number of seconds a standby CPU waits before trying to become the master CPU. The standby-to-master delay applies when two CP modules are booting at the same time. The designated standby CP waits for the configured number of seconds before attempting to assert mastership. Only one CP can be master in a chassis.

Caution

If you configure the master-to-standby delay to too short a value, the configured standby CP can become a master. If you configure the master-to-standby delay to too long, it can delay the backup CP asserting mastership and continue booting when the designated CP is inserted, but fails booting.

1. Enter Global Configuration mode:

   enable

   configure terminal

2. View the current configuration for the master CPU:

   show boot config master

3. Specify the slot of the master CPU:

   boot config master <1–2>

4. Save the changed configuration.
5. Configure the number of seconds a standby CPU waits before trying to become the master CPU:

   boot config delay <0–255>

6. Save the changed configuration.
7. Restart the switch.

Example

Switch:1>enable
Switch:1#configure terminal

Specify the slot number, either 1 or 2, for the master CPU:

Switch:1(config)# boot config master 2
Switch:1(config)# save config

Specify the number of seconds a standby CPU waits before trying to become the master CPU:

Switch:1(config)# boot config delay 30
Switch:1(config)# save config
Switch:1(config)# reset