Moving from a back-to-back topology to a switched topology in an InfiniBand network includes, prior to connecting a switch for a first storage controller in the network and during reboot of the first storage controller, waiting for a second storage controller in the network to become master, and upon the second storage controller becoming master, changing cache files for local ports on the first storage controller regarding adjacent ports' LID assignments. An aspect further includes restarting a system manager for the first storage controller, connecting the first storage controller to the system with new LID assignments provided by changed files on first storage controller, and upon the first storage controller becoming active, rebooting the second storage controller, changing the LID assignments in the active storage controller, and adding new switches to the system.