Abstract: Systems, methods and transitory computer-readable storage media for detecting one or more loops in a multicast tree. The method includes calculating a multicast tree radius for a first multicast tree, the multicast tree radius representing a maximum number of hops from a root node to a furthest edge node in the first multicast tree, forwarding, by the root node, a first packet to each edge node within the first multicast tree, the first packet having a time-to-live (TTL) value equal to twice the first multicast tree radius, receiving, at the root node, a copy of the forwarded first packet, and determining an existence of a loop in the first multicast tree based at least upon receiving the copy of the forwarded first packet.

Abstract: Systems, methods and transitory computer-readable storage media for constructing a loop free multicast tree. The methods include observing a network topology transition affecting a first path from the particular node to a root node, calculating a second path from the particular node to the root node and sending a message to an upstream node requesting that the upstream node be a root port in the calculated second path. If the upstream node agrees to be the root port in the calculated second path, the method further includes creating a new FTAG tree topology view that includes the upstream node as the root port in the second path.

Abstract: A computer network testing process to determine whether, given a network node that is unreachable by communication attempts from a controller on a control-plane network, the network node is still functioning to forward data packets on a data-plane network, or if the network node is fully non-functional on both the control-plane network and data-plane network. In order to make this determination, the testing process identifies a network node that is still reachable by the controller on the control-plane network, identifies a route between the controller and unreachable node, passing through the reachable node, and constructs an encapsulated test packet that is sent along this route. In response to sending the encapsulated test packet, the controller may, upon receipt of a confirmation packet, determine that the unreachable node is still functional on the data-plane network, or if no confirmation packet is received, mark the unreachable node as fully non-functional.

Abstract: Systems, methods, and non-transitory computer-readable storage media for dynamic addressing of virtual port channels is described. In some implementations, a virtual IP address can be dynamically generated based on which links in a virtual port channel are active. If the numbers of active links in the virtual port channel changes, the virtual IP address can be dynamically changed. The virtual IP address can be dynamically adjusted by changing the values of individual bits in the virtual IP address that correspond to links in the virtual port channel. The virtual IP address can be used as a tunnel end point address in a VXLAN environment.

Abstract: Systems, methods and transitory computer-readable storage media for running a link state routing protocol in a network that includes spine and leaf nodes. The methods include, receiving at a node in a network, one or more LSPs and re-forwarding the LSPs to other nodes. A spine node generates copies of the received LSPs and forwards the copies of the LSP to the leaf nodes in the network at a rate that is faster than the rate that the leaf nodes re-route the LSPs to the spine nodes using a hardware flooding mechanism in order to reduce the amount of processing that occurs at each spine node. In order to synchronize the LSP databases, the spine nodes send triggered CSNPs, using hardware flooding, to all leaf nodes in the network.

Abstract: A packet is generated at a first network connected device for transmission to a destination network device through a network comprising a plurality of pods. At least two of the plurality of pods are within separate management domains, and generating the packet comprises generating the packet with a first identifier and a second identifier. The first identifier indicates a pod of the plurality of pods in which the destination network connected device is located, and the second identifier indicates an identity of the destination network connected device within the pod of the plurality of pods. The packet is transmitted from the first network connected device to the destination network connected device.

Abstract: Exemplary embodiments identify all viable paths in an ECMP/WCMP enabled network without running traceroute multiple times. Devices in a network may be configured to send a packet including a pre-determined option to an Software-Defined Network Controller (SDNC) upon receipt. If a destination of the packet is within the SDNC-controlled domain, SDNC identifies all viable ECMP/WCMP paths using routing information of the network. If the destination of the packet is outside the SDNC-controlled domain, SDNC identifies at least one egress switch of the SDNC-controlled domain. SDNC may identify internal paths connecting the source of the packet to the at least one egress switch. SDNC may also identify external paths connecting the at least one egress switch to the destination of the packet. SDNC may construct the viable ECMP/WCMP paths by connecting the internal paths to the external paths.

Abstract: Certain features required for routing decisions are provided by hardware. For example, the router logic may be modified to provide multiple alternative paths for a link. In some implementations, hardware autonomously detects a link or port failure and routes on an alternate link without software intervention. In one approach, the router stores the alternate paths in the data plane. In some implementations, network devices are also configured for active loop avoidance and detection is implemented so that packets never loop due to multiple failures that occur close to each other.

Abstract: A determination is made at a network connected device that a network policy is to be verified. The network policy is applied to network packets sent to an endpoint within a network, and the application of the policy to network traffic can result in at least two outcomes. Another determination is made at the network connected device that a switch is provisionable to host the endpoint. The network connected device provisions a simulated endpoint version of the endpoint at the switch to host the policy. At least one packet is sent to the simulated endpoint via the network connected device for each of the at least two outcomes of the policy. At least one response is received by the network connected device from the simulated endpoint indicating how the policy was applied to each of the packets.

Abstract: The subject disclosure relates to implementing a device to remotely manage the data plane and configure memory components (e.g., a forwarding table, ternary content-addressable memory, etc.) on one or more application-specific integrated circuit (ASIC) based devices. The one or more ASIC based devices can be configured, for example, based on flow information collected from the OFA (open flow agent) in conjunction with the memory map of the memory components on the one or more ASIC based devices. A state of the memory components on the one or more ASIC based devices can also be remotely monitored.

Abstract: A packet is generated at a first network connected device for transmission to a destination network device through a network comprising a plurality of pods. At least two of the plurality of pods are within separate management domains, and generating the packet comprises generating the packet with a first identifier and a second identifier. The first identifier indicates a pod of the plurality of pods in which the destination network connected device is located, and the second identifier indicates an identity of the destination network connected device within the pod of the plurality of pods. The packet is transmitted from the first network connected device to the destination network connected device.

Abstract: Systems, methods, and non-transitory computer-readable storage media for a miscabling detection protocol. One or more switches can periodically send miscabling protocol (MCP) packets on non-fabric ports on all configured EPG VLANs. A first switch located at a network fabric receives a miscabling protocol (MCP) packet indicating an identity of an originating switch and a port number of an originating port of the MCP packet via a receiving port on the first switch, wherein the MCP packet is received from an external network connected to the receiving port, and wherein the originating switch and originating port are also located at the network fabric and connected to the external network. Based on the MCP packet, the first switch then detects a loop between the receiving port, the originating port, and the external network. Next, the first switch blocks the receiving port or the originating port in response to detecting the loop.

Abstract: Systems, methods, and non-transitory computer-readable storage media for on-demand learning of routing information. The system receives a first packet directed to an endpoint device in a network, the first packet including a destination address associated with the endpoint device. Next, the system determines that the destination address does not have an associated network node identified in a routing table, and lists the destination address in a pending learning cache table to yield a pending learning entry. Based on the pending learning entry, the system then modifies the routing table to identify a network address of the associated network node for the destination address, wherein modifying the routing table is performed in response to receiving a second packet from the endpoint device, and wherein the network address of the associated network node is identified based on the second packet.

Abstract: Systems, methods, and non-transitory computer-readable storage media for recovering from a partial failure of a virtual port chain (vPC) domain. The first and second vPC peers may be paired to create a vPC having a virtual address. An endpoint host may communicate with a network via the virtual port channel. The system may detect that the first virtual port channel peer is down. During or after the first vPC reboots, the reachability cost for the first vPC with regards to the virtual address can be set to an inflated value. The first vPC peer may also delay its bring up time while it synchronizes its vPC state information with the second vPC peer. The second vPC can continue to advertise the association between the endpoint host and the virtual address. Upon completion of the synchronization, the first vPC peer may bring up the link and restore the reachability cost.

Abstract: Systems, methods and transitory computer-readable storage media for constructing a loop free multicast tree. The methods include collecting data sample points to form a first data set, each of the data sample points representing a network feature variable, each network feature variable associated with a corresponding network feature, calculating a standard deviation and a mean value of the network feature variables for each network feature, performing normalization of the network feature variables to obtain normalized network feature variables, calculating, using the standard deviation and the mean value for each network feature, a probability value (p-value) for each normalized network feature variable, and determining if an anomaly exists with respect to each network feature based at least upon the p-value for each normalized network feature variable.

Abstract: An inner packet configured with a multicast address and configured to perform a traceroute operation through a network is encapsulated to form an encapsulated packet. The encapsulated packet is sent into a network, the encapsulated packet being forwarded along a multicast tree of the network for the multicast address. A plurality of responses are received from a plurality of network nodes comprising the multicast tree, wherein each response comprises an indication of a node of the plurality of nodes that sends the response and an indication of a node from which the node sending the response received the encapsulated packet.

Abstract: Various embodiments of the present disclosure provide methods for analyzing usage information at each of a plurality of network devices of a computing network according to one or more machine learning algorithms and predicting a usage pattern of a corresponding network device at a specific future time. In some embodiments, routing protocol information of a plurality of network devices and one or more corresponding upstream or downstream ports can be collected. Based upon the routing protocol information of the plurality of network devices and the corresponding upstream or downstream ports, or the predicted usage pattern at each of the plurality of network device, a reduced-power-consumption topology that scales with predicted demands at the plurality of network devices can be dynamically generated. An operation state of at least one of the plurality of network devices or at least one corresponding upstream or downstream port can be dynamically adjusted to achieve a power saving at the computing network.

Abstract: A plurality of equal cost paths through a network from a source node to a destination node are determined. A maximum bandwidth capacity for each link of each of the plurality of equal cost paths is determined, and a smallest capacity link for each of the plurality of equal cost paths is determined from the maximum capacity bandwidths for each link. An aggregated maximum bandwidth from the source node to the destination node is determined by aggregating the smallest capacity links for each of the plurality of equal cost paths. Traffic is sent from the source node along each of the plurality of equal cost paths according to a value of a capacity for the smallest capacity link for each of the plurality of equal cost paths, wherein a total of the sent traffic does not exceed the aggregated maximum bandwidth.

Abstract: A network may assign or reassign data paths to allow the network to shut down servers or switches and meet network demand at a lower energy cost. By assigning or reassigning data paths, network demand is met using only a subset of the network elements, allowing a subset of servers and switches to be temporarily shut down, thereby saving power while maintaining the ability to meet network demand.

Abstract: Systems, methods and transitory computer-readable storage media for detecting one or more loops in a multicast tree. The method includes calculating a multicast tree radius for a first multicast tree, the multicast tree radius representing a maximum number of hops from a root node to a furthest edge node in the first multicast tree, forwarding, by the root node, a first packet to each edge node within the first multicast tree, the first packet having a time-to-live (TTL) value equal to twice the first multicast tree radius, receiving, at the root node, a copy of the forwarded first packet, and determining an existence of a loop in the first multicast tree based at least upon receiving the copy of the forwarded first packet.