Abstract: After sending M consecutive DUP ACKs, M generally being three, the TCP receiver generates DUP ACKs every N packets, with N greater than one, with the eventually transmitted DUP ACK containing SACK information. After receiving the third DUP ACK the TCP transmitter uses the positive acknowledgements provided in the SACK information in the TCP header to inflate the congestion window. With the reduced DUP ACKs from the TCP receiver to the TCP transmitter, the impact of TCP DUP ACKs on the data rate from the TCP receiver to the TCP transmitter is substantially reduced.

Abstract: A hypervisor preferably provides VM (virtual machine) identification, priority and LUN/LBA range information to the HBA (host bus adapter) when a VM is created. Alternatively, the HBA can determine that a LUN/LBA range is new and request VM identity, priority and LUN/LBA range from the hypervisor. The HBA creates a table containing the VM identification, priority and LUN/LBA range. The HBA then detects operations directed to the LUN/LBA range and does a lookup to determine VM identification and priority. VM identification and priority are then mapped into a field in a frame using a unique identifier. The unique identifier can be placed using reserved bits on the existing Fiber Channel (FC) header or can use bits in an additional header, such as a modified IFR header or an optional device header. The VM identification aware HBAs register with the NS.

Abstract: Improved debugging capabilities for network packet path tracing. Embodiments trace both the control and data planes. During control plane operations each switch appends its identity to the payload, providing a full trace of the control plan path. Responses containing the forward path payload are provided back at each hop, the responses being routing back by tracing back the forward direction control plane. The data plane is monitored by setting traps along the control plane path, with responses at each hop that indicate a given switch has been used being returned along the control plane path.

Abstract: Techniques for managing ternary content-addressable memory (TCAM) in a network device/system are provided. In one embodiment, the network device/system can include one or more TCAMs and can execute a TCAM manager for each TCAM. Each TCAM manager can manage allocation of resources of its associated TCAM, as well as manage access to the TCAM by one or more network applications running on the device/system. In this way, the TCAM managers can hide TCAM implementation differences (e.g., different sizes, different capabilities, etc.) from the network applications and thereby enable the applications to interact with the TCAMs in a uniform manner.

Abstract: A management application can automatically coordinate the decommissioning of ports in a switch, ensuring that ports are gracefully taken out of service without unnecessary interruption of service and triggering of automatic recovery functionality that may occur during manual decommissioning of ports. Embodiments may provide for decommissioning of F_ports only, E_ports only, or both F_ports and E_ports. Where link aggregation is provided for in the fabric, decommissioning of a port in a link aggregation group may be performed if there are other operational links in the group. Decommissioning of a non-aggregated port (or the last operational port in a link aggregation group) may be performed if there is a redundant path available.

Abstract: A mechanism to allow switch manager software to determine bandwidth consumption and cooperate with a VM manager. Counter hardware measures network traffic between the various ports of the switch stack. The switch manager determines the MAC or IP addresses of devices connected to each port, which are provided to the VM manager to correlate VMs to ports. The switch manger collects statistics from the counter hardware to determine traffic flow levels between the various ports. A list of high traffic port pairs is provided to the VM manager. In conjunction with each port is a list of available ports, identified by at least one MAC or IP address associated with that port, having capacity to receive the traffic of the respective ports of each port pair and provided in order of least to most hops, to allow the VM manager to select a closer port to receive a migrated VM.

Abstract: Using a hash function, an L2/L3 switch can produce an FID for a data packet. The L2/L3 switch can select, from among potentially several stored VLAN flooding tables, a particular VLAN flooding table that is associated with a particular VLAN on which the data packet is to be carried. The rows of the particular VLAN flooding table can specify different combinations of the particular VLAN's egress ports. The L2/L3 switch can locate, in the particular VLAN flooding table, a particular row that specifies the FID. The L2/L3 switch can read, from the particular row, a specified subset of the egress ports that are associated with the particular VLAN. The L2/L3 switch can transmit copies of the data packet out each of the egress ports specified in the subset, toward analytic servers connected to those egress ports.

Abstract: Systems, methods and software useful for overcoming network congestion problems including head-of-line blocking issues and other network congestion problems. In certain aspects, flow control mechanisms implemented in a switch device or other network device manage buffer and system level resources using a scheduler to control the amount of data requested from a local SAN fabric. Switches and other network devices configured according to the present invention monitor each individual SCSI task, and are configured to apply flow control measures to each active session when buffering resources become scarce, such as when buffering data for a slower-speed WAN link or TCP/IP based interconnects of any speed.

Abstract: Long distance cloud migration (LDCM) to overcome the limitations faced by the cloud migration techniques over long distance, high speed WAN infrastructures. LDCM overcomes the negative effects of existing TCP/IP mechanisms on the efficient use of available bandwidth. LDCM also acts as an acceleration engine to optimize various hypervisor, storage and security applications.

Abstract: Techniques for assigning device identifiers in a system of devices are provided. In one embodiment, a master device of the system can maintain a first configuration that specifies a set of links between a first subset of the devices, where the first configuration includes a device identifier for each device in the first subset. The master device can further generate a second configuration that specifies a set of links between a second subset of the devices, where the second configuration is based on a physical topology of the system, and where one or more devices in the second subset are unknown devices that are not associated with a device identifier in the physical topology. The master device can then assign device identifiers to the unknown devices in the second subset by comparing the first configuration with the second configuration.

Abstract: Techniques for optimizing traffic flows via dynamic routing protocol (DRP) modifications when server virtualization is used with dynamic routing are provided. In one embodiment, a network device can determine that it is part of a system of network devices acting as a virtual router. The network device can then transmit, to a client device, a DRP control packet that includes an interface IP address of the network device and a virtual IP address of the virtual router. In a further embodiment, the client device can receive the DRP control packet and store the interface IP address and the virtual IP address in a routing database. At the time of computing routing entries based on the routing database, the client device can replace, in entries that identify the interface IP address as the next hop, the interface IP address with the virtual IP address.

Abstract: Techniques are identified for optimizing the MAC flush in Ethernet rings for faster traffic restoration. In one embodiment, flushing of MAC addresses is performed only once on receiving a first control message. For example, when a first control message is received, a network device may switch from a first state to a second state, which may indicate that the MAC addresses are not to be flushed if additional control messages are received. In another embodiment, flushing of MAC addresses is performed on one ring port rather than on both ring ports. For example, a flag field of a control message header may be used to determine on which port to flush. In another embodiment, flushing of MAC addresses is performed on only one ring port of an interconnection node. For example, the ring port can be determined using a flag field and possibly labels associated with the ring ports.

Abstract: The data ports in a network are displayed in a list in descending order based on either the higher transmit or receive data value of the port. Therefore, the port with the highest of either the transmit or receive data value would be displayed on the top of the list. The port with the second highest of the transmit or receive data value would be displayed second on the list. This process would continue for all data ports that are displayed. The other of the transmit or receive data values of the port would be displayed but would not affect the ordering on the display.

Abstract: Aspects of the present disclosure provide a suitable architecture for a router controller which configures forwarding rules in a packet router of a network visibility system. In an embodiment, the router controller contains multiple controller blocks, with each controller block to examine a corresponding set of packets and to generate a respective set of forwarding rules for configuring the packet router. The router controller may also contain a switch to receive multiple packets and to forward to each controller block the corresponding set of packets. Each controller block may forward the respective set of forwarding rules to the switch, with the switch in turn configuring the packet router with the respective set of forwarding rules.

Abstract: Aspects of the present disclosure enable a router controller to maintain a default rules table indicating allocation of IP addresses (of GTP packets) to respective output ports. In an embodiment, the router controller receives information indicating the respective tunnel endpoint IP addresses of a control session and a data session of a user. The router controller is configured to determine whether such IP addresses of the control session and the data session(s) are allocated to the same output port. If the IP addresses of the control session and the data session are not allocated to the same output port, router controller is configured to generate a dynamic rule to force packets of both the control session and the data session to the same output port.

Abstract: A network visibility system includes a packet router and a router controller. The router controller programs respective forwarding rules in each of a set of load-sharing components of the packet router. Each load-sharing component in the set is designed to forward communication packets according to the respective programmed packet-forwarding rules. The router controller receives, from the packet router, information indicating an update to the availability status of components in the set of components. The router controller updates the respective forwarding rules to reflect the update to the availability status.

Abstract: A network visibility system provided according to an aspect of the present disclosure forms rules for routing of packets to appropriate analytic server, based on IP addresses discovered while processing packets. Due to such discovery and forming of rules based on discovery, manual configuration of the network visibility system can be avoided. In an embodiment, the network visibility system comprises a packet router and a router controller. The router controller receives the examined packets from the packet router and configures the packet router with the formed rules.

Abstract: A sheet metal cover for a printed circuit board (PCB) includes a plurality of legs continuous with a substantially planar elevated section. The legs are attached to the PCB, and electrical connections are provided between the legs and an internal ground plane of the PCB at the attachment locations. The sheet metal cover is thereby grounded, inhibiting the transmission of electromagnetic signals through the sheet metal cover. The elevated section of the sheet metal cover prevents select electronic devices on the PCB from being viewed or probed. Openings through the sheet metal cover allow heat sinks or heat generating electronic devices (e.g., inductors) to be exposed through these openings, thereby facilitating cooling of these elements by airflow. An electrically conductive gasket attached to the underside of the elevated section may contact the heat sinks, further minimizing the radiation of EMI emissions.

Abstract: A management station which manages the encryption devices in a SAN to set up encrypted LUNs. In setting up the encryption, the source and target ports are identified, along with the target LUN. LUN serial numbers used to identify unique LUNs. As paths to a given LUN are defined, the management station compares the path to existing paths and provides an indication if there is a mismatch in the encryption policies or keys being applied to the LUN over the various paths. This allows the administrator to readily identify when there is a problem with the paths to an encrypted LUN and then take steps to cure the problem. By determining the paths and then comparing them, the management station greatly simplifies setting up multipath I/O to an encrypted LUN or access by multiple hosts to an encrypted LUN.

Abstract: A global server load balancing (GSLB) switch serves as a proxy to an authoritative DNS communicates with numerous site switches which are coupled to host servers serving specific applications. The GSLB switch receives from site switches operational information regarding host servers within the site switches neighborhood. When a client program requests a resolution of a host name, the GSLB switch, acting as a proxy of an authoritative DNS, returns one or more ordered IP addresses for the host name. The IP addresses are ordered using metrics that include the information collected from the site switches. In one instance, the GSLB switch places the address that is deemed “best” at the top of the list.