A particular fat tree network node stores default routing information indicating that the particular fat tree network node can reach a plurality of parent fat tree network nodes of the particular fat tree network node. The particular fat tree network node obtains, from a first parent fat tree network node of the plurality of parent fat tree network nodes, a negative disaggregation advertisement indicating that the first parent fat tree network node cannot reach a specific destination. The particular fat tree network node determines whether the first parent fat tree network node is the only parent fat tree network node of the plurality of parent fat tree network nodes that cannot reach the specific destination. If so, the particular fat tree network node installs supplemental routing information indicating that every parent fat tree network node except the first parent fat tree network node can reach the specific destination.

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.

Examples disclosed herein relate to a method comprising changing a state at a first device in a virtual stack forwarding (VSF) stack topology, wherein each device in the VSF stack topology has a synchronized state in a corresponding local database storing state and configuration for the device. The method may also comprise transmitting, from the first device, the changed state to a commander node of the VSF stack topology, committing, by the commander node, the changed state to a first local database of the commander node and transmitting, by the commander node, the changed state to a root node of the VSF stack topology. The method may also comprise committing, by the root node, the changed state to a second local database of the root node and propagating, by the root node, the changed state throughout the VSF stack topology.

A particular fat tree network node stores default routing information indicating that the particular fat tree network node can reach a plurality of parent fat tree network nodes of the particular fat tree network node. The particular fat tree network node obtains, from a first parent fat tree network node of the plurality of parent fat tree network nodes, a negative disaggregation advertisement indicating that the first parent fat tree network node cannot reach a specific destination. The particular fat tree network node determines whether the first parent fat tree network node is the only parent fat tree network node of the plurality of parent fat tree network nodes that cannot reach the specific destination. If so, the particular fat tree network node installs supplemental routing information indicating that every parent fat tree network node except the first parent fat tree network node can reach the specific destination.

Disclosed embodiments relate to a Hierarchical Do-Dag based RPL (H-DOC) network configuration where the network address of each node corresponds to its location within the hierarchical network. Network addresses are initialized hierarchically. Candidate patent nodes signal availability. Candidate child nodes respond to a selected candidate parent node with a temporary address. The selected candidate parent node acknowledges selection and communicates a hierarchical address for the child node in a transmission to the temporary address. The child node changes its address to the hierarchical address from the parent node. When a node switches parent nodes, it signals the old parent node to deallocate it as a child node, and then signals a selected candidate parent node with a temporary address.

Systems and methods are provided for supporting efficient reconfiguration of an interconnection network having a pre-existing routing comprising. An exemplary method can provide, a plurality of switches, the plurality switches comprising at least one leaf switch, wherein each of the one or more switches comprise a plurality of ports, and a plurality of end nodes, wherein the plurality of end nodes are interconnected via the one or more switches. The method can detect, by a subnet manager, a reconfiguration triggering event. The method can compute, by the subnet manager, a new routing for the interconnection network, wherein the computing by the subnet manager of the new routing for the interconnection network takes into consideration the pre-existing routing and selects the new routing for the interconnection network that is closest to the pre-existing routing. The method can reconfigure the interconnection network according to the new routing.

Embodiments are provided for providing optimal route reflector (ORR) root address assignment to route reflector clients and fast failover capabilities in an autonomous system, including identifying a first node in an autonomous system as a candidate root node of a first routing group, identifying a client node based on a neighbor address used in a first routing protocol, mapping the neighbor address to routing information received from the client node via a second routing protocol, and associating the neighbor address with the first routing group if the routing information includes an identifier of the first routing group. In more specific embodiments, identifying the first node as a candidate root node includes determining the first node and the first routing group are advertised in a first protocol packet, and determining the first node and the second routing group are advertised in a second protocol packet.

Systems, methods, and computer-readable media for validating routing table information in a network. A network assurance appliance may be configured to retrieve routing table information from a plurality of nodes in a network fabric. The routing table information includes path information from at least one source node to at least one destination node. A graph representation of the routing table information is constructed with the at least one destination node as a sink vertex for the graph representation. The network assurance appliance determines, for each leaf node in the network fabric, whether the leaf node can reach the sink vertex based on the graph representation and determines that there is a misconfiguration of the network fabric based on whether each leaf node in the fabric can reach the sink vertex.

A parent node selection method includes obtaining, by a network node, an identifier of each of candidate parent nodes, a quantity of subnodes already connected to each candidate parent node and a rank of each candidate parent node; obtaining a candidate rank of the network node that corresponds to each candidate parent node; determining, according to a first preset rule, a first candidate parent node set from the candidate parent nodes based on the identifier of each candidate parent node and the candidate rank of the network node that corresponds to each candidate parent node; and determining, based on a quantity of subnodes already connected to each candidate parent node in the first candidate parent node set, a candidate parent node that is in the first candidate parent node set and that is already connected to a smallest quantity of subnodes as a target parent node of the network node.

Systems, methods, and non-transitory computer-readable storage media for detecting network loops. In some embodiments, a system can identify a network path having multiple hops associated with respective nodes which are configured in a forwarding mode. The system can traverse the network path to identify, for each node from the respective nodes, a respective next hop. Based on the respective next hop for each node, the system can determine whether two or more nodes from the respective nodes have a same respective next hop. When the two or more nodes have the same respective next hop, the system can determine that the network path has a network loop.