Enabling maintenance mode on a
spine also involves BGP. The graceful_shutdown parameter will be sent out to all
the spine‘s underlay neighbors (all leafs in the pod and super-spines). The
neighbors will no longer send traffic to the first spine going into maintenance
mode and redirect traffic to an alternate path.
The running-configuration is
saved on the first spine to preserve all current configurations including the
maintenance mode enable configuration.
The firmware on the first spine
can now be upgraded and rebooted for firmware activation without traffic loss.
After the firmware is upgraded,
the maintenance mode is disabled to allow traffic again through the upgraded
spine.
The running-config is saved again to ensure the maintenance mode config remains
disabled.
The same process can be carried out on the second spine to upgrade the
firmware without traffic loss.
First spine firmware upgrade with maintenance mode
Second spine firmware upgrade with maintenance mode
