Modular industrial automation device and method for configuring a modular industrial automation device, wherein in order to configure the modular industrial automation device which includes a central unit and at least one communication module which each comprise a router module and a routing configuration unit, the routing configuration units transmit routing information stored in their routing table to routing configuration units of other router modules, and the routing configuration units update their respective routing table based on routing information which is received from routing configuration units of other router modules and relates to routes to IPv4 subnetworks assigned to other router modules, a default gateway and a connection between the associated router module and a backplane bus system.

Various example embodiments for supporting stateful explicit paths are presented herein. Various example embodiments for supporting stateful explicit paths may be configured to support communication of a packet along a path in an Internet Protocol (IP) network from a first node to a second node, wherein the path includes a set of hops, wherein the packet includes a tuple configured to identify the path, wherein the tuple includes a first IP address of the first node, a second IP address of the second node, and a path identifier of the path, wherein the path identifier of the path is a unique identifier assigned to the path, wherein the communication of the packet along the path from the first node to the second node is supported based on state information configured to map the tuple to a next hop in the set of hops of the path.

A pseudo wire load sharing method, applied to a scenario in which a first provider edge PE device is separately connected to at least one second PE device by using at least two PWs includes receiving, by the first PE device, a data flow from a customer edge CE device, and forwarding the data flow to a PW trunk interface, where the PW trunk interface is associated with at least two active PWs; and performing, by the first PE device, load sharing processing on the data flow, and forwarding the data flow by using the at least two active PWs.

A pseudo wire load sharing method, applied to a scenario in which a first provider edge PE device is separately connected to at least one second PE device by using at least two PWs includes receiving, by the first PE device, a data flow from a customer edge CE device, and forwarding the data flow to a PW trunk interface, where the PW trunk interface is associated with at least two active PWs; and performing, by the first PE device, load sharing processing on the data flow, and forwarding the data flow by using the at least two active PWs.

A novel design of a gateway that handles traffic in and out of a network by using a datapath pipeline is provided. The datapath pipeline includes multiple stages for performing various data-plane packet-processing operations at the edge of the network. The processing stages include centralized routing stages and distributed routing stages. The processing stages can include service-providing stages such as NAT and firewall. The gateway caches the result previous packet operations and reapplies the result to subsequent packets that meet certain criteria. For packets that do not have applicable or valid result from previous packet processing operations, the gateway datapath daemon executes the pipelined packet processing stages and records a set of data from each stage of the pipeline and synthesizes those data into a cache entry for subsequent packets.

A novel design of a gateway that handles traffic in and out of a network by using a datapath pipeline is provided. The datapath pipeline includes multiple stages for performing various data-plane packet-processing operations at the edge of the network. The processing stages include centralized routing stages and distributed routing stages. The processing stages can include service-providing stages such as NAT and firewall. The gateway caches the result previous packet operations and reapplies the result to subsequent packets that meet certain criteria. For packets that do not have applicable or valid result from previous packet processing operations, the gateway datapath daemon executes the pipelined packet processing stages and records a set of data from each stage of the pipeline and synthesizes those data into a cache entry for subsequent packets.

A distributed routing system is provided for use in a communication network, wherein the distributed routing system includes at least one cluster comprising a first plurality of cluster elements from which a second plurality of cluster elements is selected, wherein each of the cluster elements comprised in the second plurality of cluster elements is configured to operate as a cluster leader candidate and wherein one of that second plurality of cluster elements is selected on a temporary basis to act as cluster leader.

A distributed routing system is provided for use in a communication network, wherein the distributed routing system includes at least one cluster comprising a first plurality of cluster elements from which a second plurality of cluster elements is selected, wherein each of the cluster elements comprised in the second plurality of cluster elements is configured to operate as a cluster leader candidate and wherein one of that second plurality of cluster elements is selected on a temporary basis to act as cluster leader.

Example methods are provided for assigning a routing domain identifier in a logical network environment that includes one or more logical distributed routers and one or more logical switches. In one example, the method may comprise obtaining network topology information specifying how the one or more logical distributed routers are connected with the one or more logical switches; and selecting, from the one or more logical switches, a particular logical switch for which routing domain identifier assignment is required. The method may also comprise: identifying a particular logical distributed router that is connected with the particular logical switch based on the network topology information; assigning the particular logical switch with the routing domain identifier that is associated with the particular logical distributed router; and using the routing domain identifier in a communication between a management entity and a host.

Example methods are provided for assigning a routing domain identifier in a logical network environment that includes one or more logical distributed routers and one or more logical switches. In one example, the method may comprise obtaining network topology information specifying how the one or more logical distributed routers are connected with the one or more logical switches; and selecting, from the one or more logical switches, a particular logical switch for which routing domain identifier assignment is required. The method may also comprise: identifying a particular logical distributed router that is connected with the particular logical switch based on the network topology information; assigning the particular logical switch with the routing domain identifier that is associated with the particular logical distributed router; and using the routing domain identifier in a communication between a management entity and a host.