The invention provides for a method for running a computer network and such a computer network. The computer network comprises a number of devices being arranged in a stable daisy-chained loop, wherein each device comprises a bridge having at least three ports, whereby during running the computer network each device can take different states to avoid a loop, and whereby in case of rebooting the ports of at least one of the devices keep their current port states.

A network device including an Ethernet transmission interface and a processing unit is provided. The Ethernet transmission interface is provided with at least one Ethernet transmission port. The processing unit is coupled to the Ethernet transmission interface and is configured to: in order to detect whether a packet looping exists, send out a dynamic host configuration protocol (DHCP) discover message through a linked Ethernet transmission port in response to linking one of the at least one Ethernet transmission port to a network and determine whether a DHCP offer message is received; determine whether to prohibit data transmission of the linked Ethernet transmission port according to whether the DHCP discover message returned through the packet looping is detected; classify the linked Ethernet transmission port as an uplink transmission port or a downlink transmission port according to whether the DHCP offer message is received.

In some examples, a network device may determine an uptime of a first port and a second port, compare the uptimes of the first and second ports to a transmit interval time, and determine that the first port is connected to the network device via a more recently configured link than the second port and is the cause of the network loop when the uptime of the first port is less than the transmit interval time. The network device may determine that the second port is connected to the network device via a less recently configured link than the first port and is not the cause of the network loop when the uptime of the second port is greater than the transmit interval time and disable the first port based on the determination that the first port is connected to the network device via the more recently configured link.

The problem of routing micro-loops in networks having a CLOS topology, such as data center CLOS networks employing the exterior border gateway protocol (eBGP) for example, is solved by: (a) receiving, on an interface of one of the nodes, a datagram, the datagram including destination information; (b) determining a next hop and an egress interface using (1) an identifier of the interface on which the datagram was received, (2) the destination information of the received datagram, and (3) stored forwarding information such that a routing micro-loop is avoided without discarding the datagram; and (c) forwarding the datagram via the egress interface. For example, this problem may be solved by (a) receiving, on an interface a node of the CLOS network, a datagram, the datagram including destination information; (b) looking up, using the destination information of the received datagram and stored forwarding information, a next hop egress interface on the node; (c) determining whether or not the next hop egress interface on the node is the same as the interface on which the datagram was received; and (d) responsive to a determination that the next hop egress interface on the node is the same as the interface on which the datagram was received, (1) replacing the next hop egress interface with a safe multipath next hop egress interface, and (2) forwarding the datagram via the safe multipath next hop egress interface, and otherwise, responsive to a determination that the next hop egress interface on the node is not the same at the interface on which the datagram was received, simply forwarding the datagram via the next hop egress interface.

Embodiments of the invention relate to virtual link aggregation. One embodiment includes forming one or more virtual links using physical links connecting a first networking element, a second networking element and a third networking element. A first trigger status indication is used for blocking network traffic for avoiding traffic loops occurring over the one or more virtual links.

In one embodiment, a network device (e.g., a RPL router) executes fast local RPL recovery in a low power and lossy network (LLN). The network device, in response to becoming an orphan in a directed acyclic graph (DAG) topology, can utilize the data plane to maintain at least some data traffic by randomly forwarding the data traffic to identified neighbor devices, while eliminating children from the list of forwarders and by finding successors that can be used for re-parenting. Hence, when a RPL network device having lost its last feasible parent can avoid data loss and accelerate a re-parenting process using local repair in the data plane instead of the control plane of the routing protocol used to establish the DAG topology.

A method is implemented by a network device functioning as a switch in a software defined networking (SDN) network to detect data plane loops in the SDN network. The method includes receiving a packet, setting a value of a packet register associated with the packet to an initial loop count value, performing an arithmetic operation on the packet register to update the value of the packet register to an updated loop count value when the packet is to be resubmitted to a current flow table or a previous flow table of a packet processing pipeline of the switch, and determining that the packet is in a data plane loop in response to a determination that the updated loop count value is an invalid value.

The embodiments herein relate to a method and a network switch device for preventing the occurrence of loops in a network topology comprising a plurality of network switch devices, each switch device is assigned a unique SW-ID. The method comprises exchanging each SW-ID between all switch devices; and building, for each switch device, a routing table. The method further comprises when receiving, at a first switch device, a data frame from a second switch device that includes an SS-ID, assigned to the second switch device, and the data frame is received at a port of the first switch device, if, according to the routing table of the first switch device, the assigned SW-ID for this port is different from the SS-ID included in the data frame, discarding the data frame, otherwise, processing forward the data frame.

In an embodiment of the invention, a system determines connections between source and target nodes in a network by determining edges with common nodes between the source and target nodes within the network for each of one or more hops. Each determined edge links a pair of nodes in a network path between the source and target nodes. The system removes certain edges from the determined edges to produce a resulting set of edges. In particular, each removed edge is an edge that includes a node within a loop in the network or is an edge that is unconnected to another edge. The system determines connections between the source and target nodes based on the resulting set of edges. Embodiments of the present invention further include a method and computer program product for determining connections between source and target nodes in a network in substantially the same manners described above.

A network interface of a first computing device is configured to operate according to a bridge table. The bridge table defines a spanning tree protocol for a mesh network and identifies one or more reachable nodes. A communication characteristic between the first computing device and a second computing device of the one or more reachable nodes is determined to exceed a quality threshold. Based on the determination that the communication characteristic exceeds the quality threshold, the spanning tree protocol is overridden and the data is transmitted directly to the second computing device via a direct communication route.