Abstract: A network may include switches that have controller clients that are controlled from one or more controller servers. Clusters of the switches that have the controller clients may be isolated from other clusters by switches without the controller clients. The controller server may use graph searches to identify the clusters. The controller server may use information on the cluster topology of switches containing controller clients along with information in per-switch forwarding databases to generate per-cluster forwarding databases. The controller server may use the per-cluster forwarding databases in generating flow tables for the network switches that direct the switches to forward packets along desired paths through the network.

Abstract: A packet forwarding network may include switches that perform network forwarding operations to forward network traffic between end hosts that are coupled to the packet forwarding network. An analysis network that is controlled by a controller may be coupled to the packet forwarding network. The analysis network and the packet forwarding network may overlap. Switches such as hybrid switches in the overlapping network portions may be controlled by the controller to copy network packets without interfering with the network forwarding operations of the packet forwarding network. The analysis network may include a central portion to which analysis tools are coupled and one or more isolated portions. The controller may control the client switches of the central portion and the isolated portions to establish tunneling paths through the forwarding network.

Abstract: A method for booting a computer operating system is provided. A boot loader is loaded from a first flash memory to a random access memory and executed. In one embodiment, the boot loader loads from a second flash memory to a random access memory an operating system file system image archive, installs the operating system file system image archive as a root file system, loads from the second flash memory multiple operating system patches stored separately from the base operating system file system image archive, and installs the multiple operating system patches over the root file system. In another embodiment, the boot loader loads and executes an initialization script that performs the operations instead of the boot loader.