Examples described herein relate to a network interface device that includes circuitry that is to: receive a packet; replicate the packet based on a multicast configuration; and determine a number of replicate packets that differ from the received packet. In some examples, circuitry is to receive hash value that comprises a hash of a portion of the packet and circuitry is to determine a hash value of the replicated packet.

Examples described herein relate to a network interface device that includes circuitry that is to: receive a packet; replicate the packet based on a multicast configuration; and determine a number of replicate packets that differ from the received packet. In some examples, circuitry is to receive hash value that comprises a hash of a portion of the packet and circuitry is to determine a hash value of the replicated packet.

A network system for a data center. In one example, a method comprises establishing, by a plurality of access nodes, a logical tunnel over a plurality of data paths across a switch fabric between a source access node and a destination access node included within the plurality of access nodes, wherein the source access node is coupled to a source network device; and spraying, by the source access node, a data flow of packets over the logical tunnel to the destination access node, wherein the source access node receives the data flow of packets from the source network device, and wherein spraying the data flow of packets includes directing each of the packets within the data flow to one of the data paths based on an amount of data previously transmitted on each of the plurality of data paths.

A network system for a data center is described in which a switch fabric may provide full mesh interconnectivity such that any servers may communicate packet data to any other of the servers using any of a number of parallel data paths. Moreover, according to the techniques described herein, edge-positioned access nodes, optical permutation devices and core switches of the switch fabric may be configured and arranged in a way such that the parallel data paths provide single L2/L3 hop, full mesh interconnections between any pairwise combination of the access nodes, even in massive data centers having tens of thousands of servers. The plurality of optical permutation devices permute communications across the optical ports based on wavelength so as to provide, in some cases, full-mesh optical connectivity between edge-facing ports and core-facing ports.

In some implementations, a first processing component of a network device may receive first traffic data obtained by a second processing component of the network device. The first processing component may store the first traffic data as residual statistics. The first processing component may obtain second traffic data associated with a copy of a traffic stream processed by the first processing component based on storing the first traffic data as the residual statistics. The first processing component may perform a switchover from the second processing component to the first processing component. The first processing component may determine current traffic data based on the residual statistics and the second traffic data. The current traffic data may be determined based on performing the switchover from the second processing component to the first processing component.

A system includes input or output channels linked to nominal and redundant equipment items, and at least one redundancy matrix for routing the signals of a channel from one equipment item to a redundant or nominal equipment item, represented by a connection grid having rows corresponding to the channels of the system and columns corresponding to the equipment items of the system, and connection points comprising: the points of intersection of a nominal path situated on a nominal diagonal of the connection grid, and the points of intersection of a redundant path of the connection grid situated between each row corresponding to a channel C.sub.i and a column corresponding to a redundant element Rƒ.sub.(i) of index ƒ(i), f being surjective, the redundancy matrix being implemented in the form of a circuit comprising switches arranged according to the connection grid.

A network system for a data center is described in which an access node sprays a data flow of packets over a logical tunnel to another access node. In one example, a method comprises establishing, by a plurality of access nodes, a logical tunnel over a plurality of data paths across a switch fabric between a source access node and a destination access node included within the plurality of access nodes, wherein the source access node is coupled to a source network device; and spraying, by the source access node, a data flow of packets over the logical tunnel to the destination access node, wherein the source access node receives the data flow of packets from the source network device, and wherein spraying the data flow of packets includes directing each of the packets within the data flow to a least loaded data path.

A method used in a stacking/stackable switch unit includes: providing a plurality of signal ports of the stacking/stackable switch unit, the signal ports having at least one master/slave control port corresponding to at least one operation function of the stacking/stackable switch unit; during a boot-up procedure, automatically determining whether the stacking/stackable switch unit is a master or a slave according to at least one signal level of the at least one master/slave control port and/or content of at least one bit obtained from the at least one master/slave control port.

A method used in a stacking/stackable switch unit includes: providing a plurality of signal ports of the stacking/stackable switch unit, the signal ports having at least one master/slave control port corresponding to at least one operation function of the stacking/stackable switch unit; during a boot-up procedure, automatically determining whether the stacking/stackable switch unit is a master or a slave according to at least one signal level of the at least one master/slave control port and/or content of at least one bit obtained from the at least one master/slave control port.

A method used in a stacking/stackable switch unit includes: providing a plurality of signal ports of the stacking/stackable switch unit, the signal ports having at least one master/slave control port corresponding to at least one operation function of the stacking/stackable switch unit; during a boot-up procedure, automatically determining whether the stacking/stackable switch unit is a master or a slave according to at least one signal level of the at least one master/slave control port and/or content of at least one bit obtained from the at least one master/slave control port.