A first plurality of network configuration controllers of a controller may distribute, using a consistent hashing algorithm, a plurality of connection sessions with a plurality of network devices among the plurality of network configuration controllers. The controller may monitor a number of connection sessions maintained by each of the first plurality of network configuration controllers. The controller may add, based on monitoring the number of connection sessions maintained by each of the first plurality of network configuration controllers, an additional network configuration controller to the first plurality of network configuration controllers to form a second plurality of network configuration controllers. The second plurality of network configuration controllers may, in response to adding the additional network configuration controller to the first plurality of network configuration controllers, re-distribute, using the consistent hashing algorithm, one or more connection sessions of the plurality of connection sessions among the second plurality of network configuration controllers.

Problems associated with providing a large Clos network having at least one top of fabric (ToF) node, a plurality of internal nodes, and a plurality of leaf nodes may be solved by: (a) providing L2 tunnels between each of the leaf nodes of the Clos and one or more of the at least one ToF node to ensure a non-partitioned IGP L2 backbone, and (b) identifying the L2 tunnels as non-forwarding adjacencies in link state topology information stored in ToF node(s) and leaf node(s) such that the L2 tunnels are not used for forwarding traffic. Tunnel formation is prevented over L2.

Problems associated with providing a large Clos network having at least one top of fabric (ToF) node, a plurality of internal nodes, and a plurality of leaf nodes may be solved by: (a) providing L2 tunnels between each of the leaf nodes of the Clos and one or more of the at least one ToF node to ensure a non-partitioned IGP L2 backbone, and (b) identifying the L2 tunnels as non-forwarding adjacencies in link state topology information stored in ToF node(s) and leaf node(s) such that the L2 tunnels are not used for forwarding traffic. Tunnel formation is prevented over L2.

The disclosure provides a method for determining a configuration mismatch between a first device and a second device. During operation, a first device receives a plurality of Unidirectional Link Detection (UDLD) protocol messages from a second device. The first device is configured with a first interval configuration value corresponding to a frequency which the first device sends the UDLD protocol messages to the second device. The first device determines a second interval configuration value of the second device, which corresponds to a frequency which the second device sends the UDLD protocol messages to the first device. The first device determines that there is a configuration mismatch between the first device and the second device, and creates a log entry for the configuration mismatch, the log entry including the first and second interval configuration values.

The disclosure provides a method for determining a configuration mismatch between a first device and a second device. During operation, a first device receives a plurality of Unidirectional Link Detection (UDLD) protocol messages from a second device. The first device is configured with a first interval configuration value corresponding to a frequency which the first device sends the UDLD protocol messages to the second device. The first device determines a second interval configuration value of the second device, which corresponds to a frequency which the second device sends the UDLD protocol messages to the first device. The first device determines that there is a configuration mismatch between the first device and the second device, and creates a log entry for the configuration mismatch, the log entry including the first and second interval configuration values.

A communications method includes receiving, by a first provider edge (PE) device, a data packet from a second PE device and avoiding, by the first PE device, sending the data packet to the second PE device in response to determining that a source address of the data packet is the same as an address of the second PE device in an entry. The source address of the data packet is the same as the address of the second PE in the entry stored in the first PE device. A customer edge (CE) device is multi-homed to the first PE device and the second PE device in an all-active mode. The CE device is connected to the first PE device through a first connection and the second PE device through a second connection. The first connection and the second connection belonging to a same Ethernet segment.

A packet forwarding method includes obtaining, by a network device, a first tunnel identifier of a first packet. When the first tunnel identifier is a first value, and forwarding, by the network device, the first packet based on a first routing group in a virtual routing and forwarding (VRF) table. The first routing group consists of one or more local routes, and each next-hop outbound interface of the one or more local routes is a local outbound interface. The network device forwards the packet based on a local routing group including only a local route in the VRF table such that the packet is forwarded to a local virtual machine for processing, and is not forwarded to another tunnel endpoint device during packet forwarding.

A computer network device (such as a switch or a router) that prevents loop occurrence is described. During operation, the computer network device communicates, via one or more ports, data packets with a corresponding one or more second ports in a second computer network device, where a given data packet includes a source address and a destination address, and where the one or more ports and the second one or more ports specify a link between the computer network device and the second computer network device. Moreover, when the link goes down and then comes back up, the computer network device may block forwarding, via the one or more ports, of additional data packets based at least in part on a predefined delay.

An information obtaining unit (53) of a monitoring apparatus (40) obtains from each node, topology map information created in each node by an exchange of information and sharing of information between nodes that belong to a ring network. The topology map information is information that indicates a connection relation between the nodes in the ring network. A topology comparison unit (54) of the monitoring apparatus (40) compares the topology map information obtained from each node by the information obtaining unit (53) with topology definition information retained in a memory (42) beforehand, and determines whether or not a configuration of the ring network is according to design. The topology definition information is information that defines the connection relation between the nodes in the ring network.

A packet forwarding method and apparatus are provided, and pertain to the field of communications technologies. The method includes: determining, by a first node, information about a loop-free path from the first node to a second node, where the first node and the second node are a pair of nodes having an anycast route; and when the first node receives a packet to be sent to a third node, if a link from the first node to the third node is faulty, forwarding, by the first node, the packet to the second node based on the information about the loop-free path, so as to forward the packet to the third node through the second node. According to this application, a success rate of packet sending can be improved.