Abstract: Improved utilization of connections that can be either available or blocked is provided by associating an atemporal connection state with each connection. If a connection is available, messages are transmitted on the connection normally. If a connection is blocked, the atemporal connection state is updated to reflect the changes that were made but not transmitted. In this manner, a record is kept that allows correct transmission of the information when the connection comes back up. More specifically, after a connection status changes from blocked to available, recovery messages are automatically generated from the atemporal connection state and transmitted on the connection.

Abstract: A method for configuring network devices. The method includes selecting a first hash function to use to process packets using Equal-Cost Multi-Path (ECMP) on a network device, where the first hash function is selected from a set of hash functions using a second hash function, a network chip ID of the network chip in the network device, a network device media access control (MAC) address, and an ECMP flag. The method further includes selecting a third hash function to use to process packets using a Link Aggregation Group (LAG), where the third hash function is selected from the set of hash functions using a fourth hash function, the network chip ID of the network chip in the network device, the network device MAC address, and the LAG flag. The method further includes processing a packet received by the network device using the first hash function or the third hash function.

Abstract: A method and apparatus of a device that reads and writes data using a shared memory hash table and a lookaside buffer is described. In an exemplary embodiment, a device locates a bucket for the data in a shared memory hash table, where a writer updates the shared memory hash table and a reader that is one of a plurality of readers reads from the shared memory hash table. The device further retrieves an initial value of a version of the bucket. If the initial value of the version is odd, the device copies the data from a lookaside buffer of the writer to a local buffer for the reader, wherein the lookaside buffer stores a copy of the data while the bucket is being modified.

Abstract: A method and apparatus of a device that broadcasts data to multiple hardware forwarding engines is described. In an exemplary embodiment, a central processing unit of the device receives the data to broadcast to the plurality of hardware forwarding engines. The device further writes the data to a broadcast log. In addition, the device transmits a signal to one or more co-processors that the data is available to be read, wherein each of the plurality of hardware forwarding corresponds to one of the one or more co-processors. Each of these co-processors reads the data in the broadcast log by receiving the signal that the data is ready to be read from the broadcast log. In addition, each co-processor determines a broadcast log entry for the data for that co-processor. Each co-processor further reads the data from the broadcast log entry via a direct memory access in memory that stores the broadcast log and the plurality of hardware forwarding engines use the data to process network traffic.

Abstract: A method and apparatus of a device that determines a match for a destination address using an exact match table and a longest prefix match table of a network element is described. In an exemplary embodiment, the network element receives a data packet that includes a destination address. The network element generates a key for the destination address, wherein the key represents more addresses than the destination address. The network element further performs an address lookup using the key in an exact match table. Furthermore, a match in the address lookup indicates a first transmitting interface of the network element. The network element additionally performs an address lookup using the destination address with a longest prefix match table, wherein a match in the address lookup indicates a second transmitting interface of the network element.

Abstract: A method and apparatus of a device that includes a shared memory hash table that notifies one or more readers of changes to the shared memory hash table is described. In an exemplary embodiment, a device modifies a value in the shared memory hash table, where the value has a corresponding key. The device further stores a notification in a notification queue that indicates the value has changed. In addition, the device invalidates a previous entry in the notification queue that indicates the value has been modified. The device signals to the reader that a notification is ready to be processed.

Abstract: A method for configuring network devices. The method includes selecting a first hash function to use to process packets using Equal-Cost Multi-Path (ECMP) on a network device, where the first hash function is selected from a set of hash functions using a second hash function, a network chip ID of the network chip in the network device, a network device media access control (MAC) address, and an ECMP flag. The method further includes selecting a third hash function to use to process packets using a Link Aggregation Group (LAG), where the third hash function is selected from the set of hash functions using a fourth hash function, the network chip ID of the network chip in the network device, the network device MAC address, and the LAG flag. The method further includes processing a packet received by the network device using the first hash function or the third hash function.

Abstract: A method and apparatus of a device that determines a match for a compressed address using an exact match table of a network element is described. In an exemplary embodiment, the network element receives a data packet that has a destination address. The network element further compresses the destination address to give a compressed address. In addition, the network element performs an address lookup using the compressed address in an exact match table. Furthermore, a match in the address lookup indicates a transmitting interface of the network element. The network element forwards the data packet using the transmitting interface.

Abstract: A method and apparatus of a device that includes a shared memory hash table that notifies one or more readers of changes to the shared memory hash table is described. In an exemplary embodiment, a device modifies a value in the shared memory hash table, where the value has a corresponding key. The device further stores a notification in a notification queue that indicates the value has changed. In addition, the device invalidates a previous entry in the notification queue that indicates the value has been modified. The device signals to the reader that a notification is ready to be processed.

Abstract: A method for accurately measuring, recording and reporting latency of an Ethernet switch is disclosed. Various packet queues in the switch are monitored at any given time and forwarding latency is calculated. Latency data from multiple switching elements in a network is collected to provide end-to-end forwarding latency of a system.

Abstract: A method and apparatus of a network element that authenticates a transceiver and/or a field replaceable unit of the network element is described. The network element generates a stored transceiver signature using transceiver data stored in the removable transceiver and a nonce. In addition, the network element generates a hardware transceiver signature using data stored in secure storage of the network element and the nonce. If the stored transceiver signature and the hardware transceiver signature are equal, the network element uses the transceiver to communicate network data for the network element. Otherwise, the network element disables the transceiver.

Abstract: A method and apparatus of a device that uses a hardware shadow for a central processing unit failover is described. In an exemplary embodiment, a device receives a signal that the active central processing unit has failed, where the active central processing unit controls the processing functions of the network element and the network element includes a hardware forwarding engine and a hardware shadow. The hardware shadow additionally includes multiple shadow tables. For each shadow table, the device copies data from that shadow table to a corresponding table in the hardware forwarding engine, where the hardware shadow is a copy of the data stored in hardware tables for the hardware forwarding engine. In response to the copying, the device further switches control of the network element processing functions from the active central processing unit to a standby central processing unit.

Abstract: A method and apparatus of a device that includes a shared memory hash table that notifies one or more readers of changes to the shared memory hash table is described. In an exemplary embodiment, a device modifies a value in the shared memory hash table, where the value has a corresponding key. The device further stores a notification in a notification queue that indicates the value has changed. In addition, the device invalidates a previous entry in the notification queue that indicates the value has been modified. The device signals to the reader that a notification is ready to be processed.

Abstract: A method and apparatus of a device that reads and writes data using a shared memory hash table and a lookaside buffer is described. In an exemplary embodiment, a device locates a bucket for the data in a shared memory hash table, where a writer updates the shared memory hash table and a reader that is one of a plurality of readers reads from the shared memory hash table. The device further retrieves an initial value of a version of the bucket. If the initial value of the version is odd, the device copies the data from a lookaside buffer of the writer to a local buffer for the reader, wherein the lookaside buffer stores a copy of the data while the bucket is being modified.

Abstract: A method and apparatus of a device that broadcasts data to multiple hardware forwarding engines is described. In an exemplary embodiment, a central processing unit of the device receives the data to broadcast to the plurality of hardware forwarding engines. The device further writes the data to a broadcast log. In addition, the device transmits a signal to one or more co-processors that the data is available to be read, wherein each of the plurality of hardware forwarding corresponds to one of the one or more co-processors. Each of these co-processors reads the data in the broadcast log by receiving the signal that the data is ready to be read from the broadcast log. In addition, each co-processor determines a broadcast log entry for the data for that co-processor. Each co-processor further reads the data from the broadcast log entry via a direct memory access in memory that stores the broadcast log and the plurality of hardware forwarding engines use the data to process network traffic.

Abstract: A method and apparatus of a device that determines a cause and effect of congestion in this device is described. The device determines an effect of congestion in the device. The device measures a queue group occupancy of a queue group for a port in the device, where the queue group stores a plurality of packets to be communicated through that port. The device further determines if congestion exists on that queue group using the measurement, where the congestion prevents a packet of the plurality of packets from being communicated within a time period. If the congestion exists on that queue group, the device additionally gathers information regarding packets to be transmitted through that port. For example, the device can gather statistics packets that are stored in the queue group and/or new enqueue packets.

Abstract: A method and apparatus of a device that determines a cause and effect of congestion in this device is described. In an exemplary embodiment, the device measures a queue group occupancy of a queue group for a port in the device, where the queue group stores a plurality of packets to be communicated through that port. In addition, the device determines if the measurement indicates a potential congestion of the queue group, where the congestion prevents a packet from being communicated within a time period. If potential congestion exists on that queue group, the device further gathers information regarding packets to be transmitted through that port. For example, the device can gather statistics packets that are stored in the queue group and/or new enqueue packets.

Abstract: Improved utilization of connections that can be either available or blocked is provided by associating an atemporal connection state with each connection. If a connection is available, messages are transmitted on the connection normally. If a connection is blocked, the atemporal connection state is updated to reflect the changes that were made but not transmitted. In this manner, a record is kept that allows correct transmission of the information when the connection comes back up. More specifically, after a connection status changes from blocked to available, recovery messages are automatically generated from the atemporal connection state and transmitted on the connection.

Abstract: A method for accurately measuring, recording and reporting latency of an Ethernet switch is disclosed. Various packet queues in the switch are monitored at any given time and forwarding latency is calculated. Latency data from multiple switching elements in a network is collected to provide end-to-end forwarding latency of a system.

Abstract: A network switch device includes a switch chassis, a supervisor mounted in the switch chassis; and a line card mounted in the chassis. The line card has independently addressable line card hardware components, and a line card memory storing a software-readable description of the line card hardware components. The supervisor controller reads the software-readable description of the line card hardware components from the line card, and creates software drivers for the line card hardware components from the software-readable description of the line card hardware components.