Communication apparatus and methods

An apparatus for allowing a plurality of units to communicate with each other, the apparatus comprising:

• a plurality of ports for connection to the units and to one or more monitoring systems;
• and
• first means for transmitting packets of information to one or more of the ports, wherein each packet of information comprises forwarding information to be used in determining the packet destination,
• wherein the first means allows transmitting a packet at substantially the same time:
• (1) to one or more ports determined based on the packet destination and, in addition, (2) to one or more monitoring ports each of which is one of the plurality of ports and each of which allows connection to a monitoring system,
• the apparatus further comprising means for designating any one of the plurality of ports as a monitoring port.

An apparatus for allowing a plurality of units to communicate with each other, the apparatus comprising:

• a plurality of ports for connection to the units and to one or more monitoring systems;
• and
• first means for transmitting packets of information to one or more of the ports, wherein each packet of information comprises forwarding information to be used in determining the packet destination,
• wherein the first means allows transmitting a packet at substantially the same time:
• (1) to one or more ports determined based on the packet destination and, in addition, (2) to one or more monitoring ports each of which is one of the plurality of ports and each of which allows connection to a monitoring system, and
• wherein each of the plurality of ports allows connection to a network segment.

An apparatus for allowing a plurality of units to communicate with each other, the apparatus comprising:

• a plurality of ports for connection to the units and to one or more monitoring systems;
• and
• first means for transmitting packets of information to one or more of the ports, wherein each packet of information comprises forwarding information to be used in determining the packet destination,
• wherein the first means allows transmitting a packet at substantially the same time:
• (1) to one or more ports determined based on the packet destination and, in addition, (2) to one or more monitoring ports each of which is one of the plurality of ports and each of which allows connection to a monitoring system,
• wherein the first means comprises a store for storing one or more data structures that allow the first means to determine, using a packet's forwarding information, all the ports, if any, to which the packet is to be transmitted,
• wherein the apparatus further comprises second means to modify the data structures in response to commands so as to define which packets should be transmitted to which monitoring ports, and
• wherein the commands include a command to transmit to a monitoring port packets incoming on a selected port.

An apparatus for allowing a plurality of units to communicate with each other, the apparatus comprising:

• a plurality of ports for connection to the units and to one or more monitoring systems;
• and
• first means for transmitting packets of information to one or more of the ports, wherein each packet of information comprises forwarding information to be used in determining the packet destination,
• wherein the first means allows transmitting a packet at substantially the same time:
• (1) to one or more ports determined based on the packet destination and, in addition, (2) to one or more monitoring ports each of which is one of the plurality of ports and each of which allows connection to a monitoring system,
• wherein the first means comprises a store for storing one or more data structures that allow the first means to determine, using a packet's forwarding information, all the ports, if any, to which the packet is to be transmitted;
• wherein the apparatus further comprises second means to modify the data structures in response to commands so as to define which packets should be transmitted to which monitoring ports, and
• wherein the commands include a command to transmit to a monitoring port packets forwarded to a selected port for transmission.

An apparatus for allowing a plurality of units to communicate with each other, the apparatus comprising:

• a plurality of ports for connection to the units and to one or more monitoring systems;
• and
• first means for transmitting packets of information to one or more of the ports, wherein each packet of information comprises forwarding information to be used in determining the packet destination,
• wherein the first means allows transmitting a packet at substantially the same time:
• (1) to one or more ports determined based on the packet destination and, in addition, (2) to one or more monitoring ports each of which is one of the plurality of ports and each of which allows connection to a monitoring system,
• wherein the first means comprises a store for storing one or more data structures that allow the first means to determine, using a packet's forwarding information, all the ports, if any, to which the packet is to be transmitted,
• wherein the apparatus further comprises second means to modify the data structures in response to commands so as to define which packets should be transmitted to which monitoring ports, and
• wherein the commands include a command to transmit to a monitoring port packets incoming on a first selected port and forwarded to a second selected port for transmission.

An apparatus for allowing a plurality of units to communicate with each other, the apparatus comprising:

• a plurality of ports for connection to the units and to one or more monitoring systems;
• and
• first means for transmitting packets of information to one or more of the ports, wherein each packet of information comprises forwarding information to be used in determining the packet destination,
• wherein the first means allows transmitting a packet at substantially the same time:
• (1) to one or more ports determined based on the packet destination and, in addition, (2) to one or more monitoring ports each of which is one of the plurality of ports and each of which allows connection to a monitoring system,
• wherein the first means comprises a store for storing one or more data structures that allow the first means to determine, using a packet's forwarding information, all the ports, if any, to which the packet is to be transmitted,
• wherein the apparatus further comprises second means to modify the data structures in response to commands so as to define which packets should be transmitted to which monitoring ports, and
• wherein the commands include a command to restore the data structures to their state existing before an application of any command to transmit any packet to any monitoring port.

An apparatus for allowing a plurality of units to communicate with each other, the apparatus comprising:

• a plurality of ports for connection to the units and to one or more monitoring systems;
• and
• first means for transmitting packets of information to one or more of the ports, wherein each packet of information comprises forwarding information to be used in determining the packet destination,
• wherein the first means allows transmitting a packet at substantially the same time:
• (1) to one or more ports determined based on the packet destination and, in addition, (2) to one or more monitoring ports each of which is one of the plurality of ports and each of which allows connection to a monitoring system, and
• wherein the first means comprises means for applying one or more custom filtering rules to determine which packets are to be transmitted to a monitoring port.

An apparatus for allowing a plurality of units to communicate with each other, the apparatus comprising:

• a plurality of ports for connection to the units and to one or more monitoring systems;
• first means for transmitting packets of information to one or more of the ports, wherein each packet of information comprises forwarding information to be used in determining the packet destination;
• and
• second means for specifying to the first means which packets are to be transmitted to one or more monitoring ports each of which is one of the plurality of ports and each of which allows connection to a monitoring system,
• wherein the first means comprises means for transmitting each specified packet:
• (1) to one or more ports determined from the packet destination if the packet destination includes a unit other than the apparatus;
• and, in addition, (2) to one or more monitoring ports, and
• wherein the second means comprises means for designating any one of the plurality of ports as a monitoring port.

An apparatus for allowing a plurality of units to communicate with each other, the apparatus comprising:

• a plurality of ports for connection to the units and to one or more monitoring systems;
• first means for transmitting packets of information to one or more of the ports, wherein each packet of information comprises forwarding information to be used in determining the packet destination;
• and
• second means for specifying to the first means which packets are to be transmitted to one or more monitoring ports each of which is one of the plurality of ports and each of which allows connection to a monitoring system,
• wherein the first means comprises means for transmitting each specified packet:
• (1) to one or more ports determined from the packet destination if the packet destination includes a unit other than the apparatus;
• and, in addition, (2) to one or more monitoring ports, and
• wherein each of the plurality of ports allows connection to a network segment.

An apparatus for allowing a plurality of units to communicate with each other, the apparatus comprising:

• a plurality of ports for connection to the units and to one or more monitoring systems;
• first means for transmitting packets of information to one or more of the ports, wherein each packet of information comprises forwarding information to be used in determining the packet destination;
• and
• second means for specifying to the first means which packets are to be transmitted to one or more monitoring ports each of which is one of the plurality of ports and each of which allows connection to a monitoring system,
• wherein the first means comprises means for transmitting each specified packet:
• (1) to one or more ports determined from the packet destination if the packet destination includes a unit other than the apparatus;
• and, in addition, (2) to one or more monitoring ports,
• wherein the first means comprises a store for storing one or more data structures that allow the first means to determine, using a packet's forwarding information, all the ports, if any, to which the packet is to be transmitted,
• wherein the second means comprises means to modify the data structures in response to commands so as to specify to the first means which packets should be transmitted to which monitoring ports, and
• wherein the commands include a command to transmit to a monitoring port packets incoming on a selected port.

An apparatus for allowing a plurality of units to communicate with each other, the apparatus comprising:

• a plurality of ports for connection to the units and to one or more monitoring systems;
• first means for transmitting packets of information to one or more of the ports, wherein each packet of information comprises forwarding information to be used in determining the packet destination;
• and
• second means for specifying to the first means which packets are to be transmitted to one or more monitoring ports each of which is one of the plurality of ports and each of which allows connection to a monitoring system,
• wherein the first means comprises means for transmitting each specified packet:
• (1) to one or more ports determined from the packet destination if the packet destination includes a unit other than the apparatus;
• and, in addition, (2) to one or more monitoring ports,
• wherein the first means comprises a store for storing one or more data structures that allow the first means to determine, using a packet's forwarding information, all the ports, if any, to which the packet is to be transmitted,
• wherein the second means comprises means to modify the data structures in response to commands so as to specify to the first means which packets should be transmitted to which monitoring ports, and
• wherein the commands include a command to transmit to a monitoring port packets forwarded to a selected port for transmission.

An apparatus for allowing a plurality of units to communicate with each other, the apparatus comprising:

• a plurality of ports for connection to the units and to one or more monitoring systems;
• first means for transmitting packets of information to one or more of the ports, wherein each packet of information comprises forwarding information to be used in determining the packet destination;
• and
• second means for specifying to the first means which packets are to be transmitted to one or more monitoring ports each of which is one of the plurality of ports and each of which allows connection to a monitoring system,
• wherein the first means comprises means for transmitting each specified packet:
• (1) to one or more ports determined from the packet destination if the packet destination includes a unit other than the apparatus;
• and, in addition, (2) to one or more monitoring ports,
• wherein the first means comprises a store for storing one or more data structures that allow the first means to determine, using a packet's forwarding information, all the ports, if any, to which the packet is to be transmitted,
• wherein the second means comprises means to modify the data structures in response to commands so as to specify to the first means which packets should be transmitted to which monitoring ports, and
• wherein the commands include a command to transmit to a monitoring port packets incoming on a first selected port and forwarded to a second selected port for transmission.

An apparatus for allowing a plurality of units to communicate with each other, the apparatus comprising:

• a plurality of ports for connection to the units and to one or more monitoring systems;
• first means for transmitting packets of information to one or more of the ports, wherein each packet of information comprises forwarding information to be used in determining the packet destination;
• and
• second means for specifying to the first means which packets are to be transmitted to one or more monitoring ports each of which is one of the plurality of ports and each of which allows connection to a monitoring system,
• wherein the first means comprises means for transmitting each specified packet:
• (1) to one or more ports determined from the packet destination if the packet destination includes a unit other than the apparatus;
• and, in addition, (2) to one or more monitoring ports,
• wherein the first means comprises a store for storing one or more data structures that allow the first means to determine, using a packet's forwarding information, all the ports, if any, to which the packet is to be transmitted,
• wherein the second means comprises means to modify the data structures in response to commands so as to specify to the first means which packets should be transmitted to which monitoring ports, and
• wherein the commands include a command to restore the data structures to their state existing before an application of any command to transmit any packet to any monitoring port.

An apparatus for allowing a plurality of units to communicate with each other, the apparatus comprising:

• a plurality of ports for connection to the units and to one or more monitoring systems;
• first means for transmitting packets of information to one or more of the ports, wherein each packet of information comprises forwarding information to be used in determining the packet destination;
• and
• second means for specifying to the first means which packets are to be transmitted to one or more monitoring ports each of which is one of the plurality of ports and each of which allows connection to a monitoring system,
• wherein the first means comprises means for transmitting each specified packet:
• (1) to one or more ports determined from the packet destination if the packet destination includes a unit other than the apparatus;
• and, in addition, (2) to one or more monitoring ports, and
• wherein the first means comprises means for applying one or more custom filtering rules to determine which packets are to be transmitted to a monitoring port.

A method for monitoring a network comprising an apparatus interconnecting a plurality of network segments at least one of which comprises a network monitor, the method comprising:

• (a) obtaining, from each packet received by the apparatus, forwarding information to be used in determining the packet destination;
• (b) if a packet destination includes a station other than the apparatus, then transmitting the packet to one or more of the network segments in order to deliver the packet to the packet destination;
• (c) if a packet is to be delivered to a network monitor, then transmitting the packet to a network segment comprising the network monitor;
• storing in a store one or more data structures for determining, using a packet's forwarding information, all the network segments, if any, to which the packet is to be transmitted;
• and
• modifying the data structures in response to a command so as to define which packets should be transmitted to which network segments comprising network monitors.

A method for monitoring a network comprising an apparatus interconnecting a plurality of network segments at least one of which comprises a network monitor, the method comprising:

• (a) obtaining, from each packet received by the apparatus, forwarding information to be used in determining the packet destination;
• (b) if a packet destination includes a station other than the apparatus, then transmitting the packet to one or more of the network segments in order to deliver the packet to the packet destination;
• and
• (c) if a packet is to be delivered to a network monitor, then transmitting the packet to a network segment comprising the network monitor,
• wherein the step (c) comprises applying one or more custom filtering rules to determine whether a packet is to be delivered to a network monitor.