What does the "keepalive-enable" command do?
So it looks like this command is added by default when you enable SSO on a 6500 series switch with dual SUP720's.
My guess is it is a safety mechanism to communicate keepalives between the two SUP's to monitor for a software freeze.
We We can see below it looks like keepalives are exchanged every 9000 milliseconds, and after 18 timeouts a switchover occurs??
Can't find any explanation of this feature on cisco's docs.
wmrUSNYMD06DC#sh redundancy sta
my state = 13 -ACTIVE
peer state = 8 -STANDBY HOT
Mode = Duplex
Unit = Secondary
Unit ID = 6
Redundancy Mode (Operational) = sso
Redundancy Mode (Configured) = sso
Redundancy State = sso
Maintenance Mode = Disabled
Communications = Up
client count = 76
client_notification_TMR = 30000 milliseconds
keep_alive TMR = 9000 milliseconds
keep_alive count = 0
keep_alive threshold = 18
RF debug mask = 0x0