Abstract: In one embodiment, a method includes receiving a multi-destination packet at a switch in communication with a plurality of servers through a network device, identifying a port receiving the multi-destination packet at the switch or a forwarding topology for the multi-destination packet, selecting a bit value based on the identified port or forwarding topology, inserting the bit value into a field in a virtual network tag in the multi-destination packet, and forwarding the multi-destination packet with the virtual network tag to the network device. The network device is configured to forward the multi-destination packet to one or more of the servers based on the bit value in the multi-destination packet. An apparatus for forwarding multi-destination packets is also disclosed.

Abstract: In one embodiment, a method includes receiving a multi-destination packet at a switch in communication with a plurality of servers through a network device, identifying a port receiving the multi-destination packet at the switch or a forwarding topology for the multi-destination packet, selecting a bit value based on the identified port or forwarding topology, inserting the bit value into a field in a virtual network tag in the multi-destination packet, and forwarding the multi-destination packet with the virtual network tag to the network device. The network device is configured to forward the multi-destination packet to one or more of the servers based on the bit value in the multi-destination packet. An apparatus for forwarding multi-destination packets is also disclosed.

Abstract: Methods and apparatus for transmitting a plurality of packets in a switch having a plurality of input ports and a plurality of output ports are disclosed. Two or more packets are received at one or more of the plurality of input ports. One of the plurality of output ports via which to send each of the two or more packets is identified. A request message is sent to an arbitrator. A grant message is then received from the arbitrator in response to the request message. A frame including the two or more received packets is generated. The frame is then sent to the one of the plurality of output ports when the grant message is received.

Abstract: In one embodiment, a first packet is forwarded based on a network layer routing decision rendered by a router. A shortcut entry is generated based on a first header of the first packet. The shortcut entry is stored. In response to the shortcut entry, and absent a network layer routing decision rendered by a router, subsequent packets having a subsequent header are forwarded if the subsequent header has at least one field which matches a field of the first header. Such technique may be implemented by a switch coupled to the router.

Abstract: Methods and apparatus are provided for credit-based flow control. Techniques allow a receiver to provide buffer characteristic information to a sender using a single extended receiver ready signal. Multiple credits can be allocated using a single extended receiver ready signal as well. Counters and registers are used to allow for the accidental loss of extended receiver ready signals while still maintaining an accurate reflection of the types and numbers of buffers available.

Abstract: A shortcut technique implements forwarding decision shortcuts at a switch for frames routed between subnetworks of a computer network. The switch monitors the flow of a first frame of a particular type to and from the router, which renders a forwarding decision for routing the frame. The switch records information stored in network layer header of a packet encapsulated within the first frame, and then compares that information with the information stored in network layer headers of packets contained within subsequent frames of that particular type. Forwarding decisions for these subsequent frames are then rendered by hardware logic circuits of the switch rather than by the router.

Abstract: Methods and apparatus for performing arbitration to coordinate the sending of a plurality of packets or frames received at one or more input ports for transmission by one or more output ports are disclosed. One or more request messages are received from one or more of the input ports, each of the request messages indicating a request to send one or more packets or frames via one of the output ports. The arbitrator then determines whether the one of the output ports is capable of receiving the one or more packets or frames. A grant message is generated or sent when it is determined that the one of the output ports is capable of receiving the one or more packets or frames, the grant message indicating that the one of the output ports is capable of receiving the one or more packets or frames.

Abstract: Methods and apparatus are provided for credit-based flow control. Techniques allow a receiver to provide buffer characteristic information to a sender using a single extended receiver ready signal. Multiple credits can be allocated using a single extended receiver ready signal as well. Counters and registers are used to allow for the accidental loss of extended receiver ready signals while still maintaining an accurate reflection of the types and numbers of buffers available.

Abstract: A shortcut technique implements forwarding decision shortcuts at a switch for frames routed between subnetworks of a computer network. The switch monitors the flow of a first frame of a particular type to and from the router, which renders a forwarding decision for routing the frame. The switch records information stored in network layer header of a packet encapsulated within the first frame, and then compares that information with the information stored in network layer headers of packets contained within subsequent frames of that particular type. Forwarding decisions for these subsequent frames are then rendered by hardware logic circuits of the switch rather than by the router.