Enabling maintenance mode on a
super-spine involves BGP. The graceful_shutdown parameter will be sent to all
the super-spine‘s underlay neighbors (all connected spines). Each neighbor will
process the graceful_shutdown and refresh their routes to use the alternate
path. Maintenance mode is enabled on the first super-spine and traffic is
diverted over to the second super-spine.
The running-configuration is
saved on the first super-spine to preserve all current configurations including
the maintenance mode enable configuration.
The firmware on the first
super-spine can now be upgraded and rebooted for firmware activation without
traffic loss.
Once the new firmware is
activated, maintenance mode can be disabled. The graceful_shutdown parameter is
removed from all the underlay neighbors and traffic to the first super-spine is
allowed again.
The running-config is persisted again to ensure the maintenance mode disabled
state is retained.
The same process can be carried out on the second super-spine to upgrade the
firmware without traffic loss.
First super-spine firmware upgrade with
maintenance mode
Second super-spine firmware upgrade with
maintenance mode
