Abstract: Some embodiments provide a method for a load balancer executing in a public cloud to load balance requests to datacenters from a network management system implemented in the public cloud. The method receives a message from a network management service for a local network manager at a particular datacenter of multiple datacenters managed by the network management system. The method maps a datacenter identifier for the particular datacenter included in the request to a particular connection server that handles a persistent connection between the local network manager at the particular datacenter and the network management system. Persistent connections between the datacenters and the network management system are handled by multiple different connection servers. The method sends the message to the particular connection server for the particular connection server to transmit the message to the local network manager via the persistent connection.

Abstract: Some embodiments provide a method for a connection server that handles a connection between a network management system in a public cloud and a datacenter belonging to a datacenter group managed by the network management system. The method receives an API request, having a first format, for a local network manager located at the datacenter. The method translates the API request into a second format used by the connection between the network management system and the datacenter. The connection is a type that (i) allows for the connection server to push data onto the connection when the connection is initiated by a connection agent at the datacenter and (ii) uses the second format. The method sends the translated API request in the second format to the connection agent via the connection. The connection agent translates the API request into the first format for execution at the local network manager.

Abstract: Some embodiments provide a method for a connection server that handles connections between a network management system in a public cloud and datacenters managed by the network management system. The method receives (i) a first application programming interface (API) request for a first local network manager located at a first datacenter belonging to a first datacenter group of a first tenant and (ii) a second API request for a second local network manager located at a second datacenter belonging to a second datacenter group of a second tenant. Based on site identifiers respectively associated with the first and second datacenters and included in the first and second API requests, the method respectively sends the first and second API requests to the first and second local network managers via first and second connections previously initiated by the first and second local network managers.

Abstract: Some embodiments provide a method for initiating a connection between a network management system in a public cloud and a datacenter managed by the network management system. The method is performed at a controller executing in the public cloud. The method receives a registration message from a particular datacenter to be managed by the network management system. The method identifies one of multiple connection servers in the public cloud for handling a persistent connection initiated by the datacenter. The method configures a load balancer in the public cloud to statically select the identified connection server for data messages that include a datacenter identifier associated with the particular datacenter.

Abstract: Systems and methods for enabling Bidirectional Forwarding Detection (BFD) over a selected reverse path are provided. A process, according to one implementation, include sending an echo request in a forward direction from an initiator node to a reflector node. For example, the initiator node and reflector node may be configured to operate in a network having no or different centralized controller that manages both the initiator node and reflector node. The echo request may be sent to the reflector node to discover a reverse path in a reverse direction from the reflector node to the initiator node. Also, the reverse path is discovered for the purpose of initiating a Bidirectional Forwarding Detection (BFD) or Multi-Protocol Label Switching (MPLS) Ping procedure.

Abstract: Systems and methods for monitoring the continuity between endpoints in a network are provided. A process, according to one implementation, includes entering a first list of one or more Segment Identifiers (SIDs) into a Bidirectional Forwarding Detection (BFD) request packet, the first list of one or more SIDs defining a Segment-Routing Traffic-Engineering (SR-TE) forward path from a source node to a destination node. The process also includes entering a second list of one or more SIDs into the BFD request packet, the second list of one or more SIDs defining an SR-TE reverse path back from the destination node that eliminates involvement of a BFD reflector of the destination node. Also, the process includes entering a revised-BFD request into the BFD request packet, the revised-BFD request having a Your Discriminator field set to a discriminator value associated with the source node.

Abstract: Systems, methods, and computer-readable media are provided for re-establishing a Bidirectional Forwarding Detection (BFD) session. A method, according to one implementation, include a step of receiving, at a local end device, a first BFD control packet from a remote end device when a BFD session between the local end device and remote end device is down. For example, the first BFD control packet may include a remote discriminator number associated with the remote end device and a local discriminator number presumed to be associated with the local end device. The method further includes a step of replying to the remote end device with a second BFD control packet including an actual discriminator number of the local end device in response to determining that the local discriminator number included in the first BFD control packet is non-zero and differs from the actual discriminator number of the local end device.

Abstract: Systems and methods for performing connectivity checks, such as Seamless Bidirectional Forwarding Detection (S-BFD), are provided. A method, according to one implementation, includes receiving, at a responding node, an entry configured to call for a modification of an identification element (from an old identifier value to a new identifier value) used for identifying the responding node with respect to other nodes of a network. The old and new identifier values are cached in a memory device. Also, the method includes providing a reply packet back to an initiating node in response to receipt of a request packet from the initiating node. The request packet is related to a connectivity check for testing the connectivity between the initiating node and the responding node. In addition, the request packet is able to identify the responding node by either the old identifier value or the new identifier value.

Abstract: Systems and methods for enabling Bidirectional Forwarding Detection (BFD) over a selected reverse path are provided. A process, according to one implementation, include sending an echo request in a forward direction from an initiator node to a reflector node. For example, the initiator node and reflector node may be configured to operate in a network having no or different centralized controller that manages both the initiator node and reflector node. The echo request may be sent to the reflector node to discover a reverse path in a reverse direction from the reflector node to the initiator node. Also, the reverse path is discovered for the purpose of initiating a Bidirectional Forwarding Detection (BFD) or Multi-Protocol Label Switching (MPLS) Ping procedure.

Abstract: Systems, methods, and computer-readable media are provided for re-establishing a Bidirectional Forwarding Detection (BFD) session. A method, according to one implementation, include a step of receiving, at a local end device, a first BFD control packet from a remote end device when a BFD session between the local end device and remote end device is down. For example, the first BFD control packet may include a remote discriminator number associated with the remote end device and a local discriminator number presumed to be associated with the local end device. The method further includes a step of replying to the remote end device with a second BFD control packet including an actual discriminator number of the local end device in response to determining that the local discriminator number included in the first BFD control packet is non-zero and differs from the actual discriminator number of the local end device.

Abstract: Systems and methods for incorporating a new channel-type value in the header of a Generic Associated Channel (G-ACh) for Connectivity Fault Management (CFM) Layer-2 packets over Multi-Protocol Label Switching (MPLS) networks are provided. The channel-type value of the G-ACh header may be used for identification of the network-generated CFM Layer-2 packets. In one implementation, a system may include a processing device and a memory device, where the memory device may be configured to store instructions that, when executed, cause the processing device to obtain a Connectivity Fault Management (CFM) packet, encapsulate the CFM packet with Pseudo-Wire (PW) and Label-Switched Path (LSP) labels to create an expanded packet, and incorporate a specific channel-type value in a G-ACh header of the expanded packet to uniquely identify the CFM packet.

Abstract: Systems and methods for incorporating a new channel-type value in the header of a Generic Associated Channel (G-ACh) for Connectivity Fault Management (CFM) Layer-2 packets over Multi-Protocol Label Switching (MPLS) networks are provided. The channel-type value of the G-ACh header may be used for identification of the network-generated CFM Layer-2 packets. In one implementation, a system may include a processing device and a memory device, where the memory device may be configured to store instructions that, when executed, cause the processing device to obtain a Connectivity Fault Management (CFM) packet, encapsulate the CFM packet with Pseudo-Wire (PW) and Label-Switched Path (LSP) labels to create an expanded packet, and incorporate a specific channel-type value in a G-ACh header of the expanded packet to uniquely identify the CFM packet.

Abstract: Methods, systems, and computer readable media for sustaining active control over concurrent session connections are disclosed. According to one example, the disclosed subject matter describes herein a method that includes opening a plurality of session connections to a device under test (DUT), wherein each of the opened session connections is associated with an initial window size value and receiving data from the DUT via one or more of the opened session connections. The method further includes communicating a packet instructing the DUT to cease sending the data via the one or more of the opened session connections in the event the data received from the DUT equals the initial session window size value and utilizing at least one of the opened session connections not being used to receive the data from the DUT in order to resume active communication of the data with the DUT.

Abstract: Methods, systems, and computer readable media for sustaining active control over concurrent session connections are disclosed. According to one example, the disclosed subject matter describes herein a method that includes opening a plurality of session connections to a device under test (DUT), wherein each of the opened session connections is associated with an initial window size value and receiving data from the DUT via one or more of the opened session connections. The method further includes communicating a packet instructing the DUT to cease sending the data via the one or more of the opened session connections in the event the data received from the DUT equals the initial session window size value and utilizing at least one of the opened session connections not being used to receive the data from the DUT in order to resume active communication of the data with the DUT.