When you get your brand new Cisco ASR1000 series router, Stateful Switchover (SSO) is disabled by default:
Router# show redundancy states
my state = 13 -ACTIVE
peer state = 1 -DISABLED
Mode = Simplex
Unit ID = 6
Redundancy Mode (Operational) = Non-redundant
Redundancy Mode (Configured) = Non-redundant
Redundancy State = Non Redundant
Enable SSO!
Router# config t
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)# redundancy
Router(config-red)# mode sso
Router(config-red)# ^Z
%CMRP-6-DUAL_IOS_REBOOT_REQUIRED: R0/0: cmand: Configuration must be saved and the chassis must be rebooted for IOS redundancy changes to take effect
Router# reload
And once it's back live, you can see that SSO is up and working:
Router# show redundancy states
my state = 13 -ACTIVE
peer state = 8 -STANDBY HOT
Mode = Duplex
Unit = Primary
Unit ID = 48
Redundancy Mode (Operational) = sso
Redundancy Mode (Configured) = sso
Redundancy State = sso
Manual Swact = enabled
Communications = Up
client count = 87
client_notification_TMR = 30000 milliseconds
keep_alive TMR = 4000 milliseconds
keep_alive count = 0
keep_alive threshold = 7
RF debug mask = 0x0
