Enabling maintenance mode on one
of the leafs in the centralized MCT leaf pair follows the same behavior as the
MCT leaf pair in Clos topology. The only difference is the iBGP L3 backup link
between MCT leaf pairs. Maintenace mode will result in the traffic being
redirected to the peer leaf in the centralized MCT leaf pairs.
The running-configuration is
saved on the first MCT leaf to preserve all current configurations including the
maintenance mode enable configuration.
The firmware on the MCT leaf 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 MCT leaf.
The running-config is saved again to ensure the maintenance mode config
remains disabled.
The same process can be carried out on the second MCT leaf to upgrade the
firmware without traffic loss.
Three rack centralized first MCT leaf firmware upgrade with
maintenance mode
Three rack centralized Second MCT leaf firmware upgrade with
maintenance mode
