Abstract: A controller may control client switches in a network including client and non-client switches. The controller may maintain a link discovery table including entries that identify links between client switches. The controller may classify the links as direct or broadcast links. To classify links of the link discovery cable, the controller may direct client switches to send broadcast and directed discovery packets from switch ports. Client switches that receive the discovery packets from other client switches may forward the discovery packets to the controller. The controller may use the discovery packets to classify the links of the link discovery table. The controller may classify ports as broadcast or regular ports based on the classified links. Non-client broadcast domains of the network topology may be identified from the broadcast ports using the broadcast and direct links of the link discovery table.

Abstract: A controller may control client switches in a network including client and non-client switches. The controller may maintain a link discovery table including entries that identify links between client switches. The controller may classify the links as direct or broadcast links. To classify links of the link discovery table, the controller may direct client switches to send broadcast and directed discovery packets from switch ports. Client switches that receive the discovery packets from other client switches may forward the discovery packets to the controller. The controller may use the discovery packets to classify the links of the link discovery table. The controller may classify ports as broadcast or regular ports based on the classified links. Non-client broadcast domains of the network topology may be identified from the broadcast ports using the broadcast and direct links of the link discovery table.

Abstract: A controller may control client switches in a network including client and non-client switches. The controller may maintain a link discovery table including entries that identify links between client switches. The controller may classify the links as direct or broadcast links. To classify links of the link discovery table, the controller may direct client switches to send broadcast and directed discovery packets from switch ports. Client switches that receive the discovery packets from other client switches may forward the discovery packets to the controller. The controller may use the discovery packets to classify the links of the link discovery table. The controller may classify ports as broadcast or regular ports based on the classified links. Non-client broadcast domains of the network topology may be identified from the broadcast ports using the broadcast and direct links of the link discovery table.

Abstract: A network controlled by a controller may include end hosts that are coupled to the switches. The network may be coupled to gateways that interface between the network and an external network. The network may include subnetworks formed from respective portions of the end hosts of the network. The controller may create virtual gateways that interface between each of the subnetworks and the network by providing the end hosts of each subnetwork with virtual gateway Ethernet addresses. The controller may receive a network packet having a virtual gateway Ethernet address from an end host of a given subnetwork. The network packet may be destined for an end host of an external network or subnetwork. The controller may forward the network packet to the destination end host by redirecting the network packet through a selected gateway or by controlling the switches to perform gateway functions.

Abstract: A network controlled by a controller may include end hosts that are coupled to the switches. The network may be coupled to gateways that interface between the network and an external network. The network may include subnetworks formed from respective portions of the end hosts of the network. The controller may create virtual gateways that interface between each of the subnetworks and the network by providing the end hosts of each subnetwork with virtual gateway Ethernet addresses. The controller may receive a network packet having a virtual gateway Ethernet address from an end host of a given subnetwork. The network packet may be destined for an end host of an external network or subnetwork. The controller may forward the network packet to the destination end host by redirecting the network packet through a selected gateway or by controlling the switches to perform gateway functions.