Patent ID: 8489718

Claim:
A computer-implemented method of connecting computing devices, comprising: under control of one or more computer systems configured with executable instructions, providing a plurality of deployment units each comprising a first tier of edge switches each connected to each of a second tier of spine switches, each edge switch being further connected to a respective set of computing devices, the edge switches and spine switches being connected using only connections between tiers, wherein each switch in a deployment unit maintains information about other switches located only within the same deployment unit, and wherein only a portion of the edge switches in the deployment unit are configured as egress switches having external connections to one or more devices outside of the deployment unit; connecting the plurality of deployment units to an external network using a backbone tier comprising a plurality of backbone switches, connections for network traffic between the computing devices and the external network being only between-tier connections; and connecting the plurality of backbone switches using a plurality of connections within the backbone tier, each connection between backbone switches used to transmit routing information for conventional routing protocols, the plurality of backbone switches being connected using a torroidal connection design wherein each of the backbone switches is connected to at most four of the plurality of backbone switches, wherein the backbone switches are enabled to pass routing information upon unavailability of up to three of the backbone switches in the backbone tier.