US 7,680,114 B2Granted

Packet forwarding device with packet filter

AssigneeAlaxala Networks Corporation

InventorsTakeki Yazaki, Toshio Shimojo

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Abstract

To provide a packet forwarding device which minimizes degradation in packet forwarding performance at the time of execution of filtering there is provided a technique in which a destination decision processing unit of a destination decision and filtering unit decides whether to execute filtering on the basis of at least one of an input interface, an input port number, an output interface, and an output port number of an input packet and a plurality of pieces of information constituting the header of the packet. A filtering unit executes filtering only for a packet for which execution of filtering is decided. The packet forwarding device with the destination decision and filtering unit need not execute filtering for all packets and can minimize degradation in packet forwarding performance caused by filtering.

Claims15

Dependent claims

A forwarding device which forwards a packet, comprising:

a packet receiving unit which receives a packet from a port;
and
an execution decision unit which decides whether to execute filtering on the basis of one of information of a first packet received by said packet receiving unit and input information of said packet receiving unit;
a routing information unit storing therein routing information including a set of address information versus destination address of said address information;
a destination decision unit searching said routing information unit for output destination information corresponding to a destination of the first packet to decide the output destination information;
and
a filtering unit searching said routing information unit for filtering information for a source of said packet thereby to decide whether or not to discard the first packet;
wherein said execution decision unit decides whether to execute filtering on the basis of the output destination information decided by said destination decision unit;
and
wherein the output destination information includes an interface number indicating a network to which the first packet is to be output, an output port number indicating a number of a port to which the first packet is to be output, and at least a part of a next hop address indicating an address of a next forwarding device to which the first packet is to be transmitted.

7 more elements

A forwarding device having a plurality of interface units each connected to an extra-device port and an intra-device line, comprising:

a packet receiving unit which receives a first packet from a first extra- device port of a first interface unit of the plurality of interface units;
a routing information unit storing therein routing information including a set of address information versus destination address of said address information;
an input-side destination decision unit which searches said routing information unit for output destination information corresponding to a destination of the first packet to decide output destination information corresponding to a destination contained in the first packet received by said packet receiving unit;
a filtering execution decision unit which decides whether to execute filtering on the basis of the output destination information decided by said input-side destination decision unit;
a filtering result decision unit which searches said routing information unit for output destination information corresponding to a destination of the first packet to decide the output destination information to decide whether to allow forwarding of the first packet if said filtering execution decision unit decides execution of filtering;
and
a packet transmitting unit which transmits information of the first packet to the output destination information decided by said input-side destination unit through the intra-device line if said filtering execution decision unit decides non- execution of filtering or if said filtering result decision unit decides allowance of forwarding;
and
an interface number decision unit which decides a first input interface number on the basis of one of a Dort number corresponding to the first extra-device port from which the first packet is received and information in a header of the packet,
wherein said filtering result decision unit decides whether to allow forwarding on the basis of the first interface number corresponding to the first extra-device port decided by said interface number decision unit in addition to the source address contained in the first packet.

7 more elements

A forwarding device having a plurality of interface units each connected to an extra-device port and an intra-device line, comprising:

a packet receiving unit which receives a first packet from a first extra-device port of a first interface unit of the plurality of interface units;
a routing information unit storing therein routing information including a set of address information versus destination address of said address information;
an intra-device forwarding unit which searches said routing information unit for output destination information corresponding to a destination of the first packet to forward information of the first packet, to which input source information corresponding to the first extra-device port is added, to a second interface unit corresponding to said output destination information contained in the first packet received by said packet receiving unit;
a filtering execution decision unit which decides whether to execute filtering on the basis of at least one of the information of the first packet received by the second interface unit and the input source information;
a filtering result decision unit which searches said routing information unit for output destination information corresponding to a destination of the first packet to decide the output destination information to decide whether to allow forwarding of the first packet if said filtering execution decision unit decides execution of filtering;
and
a packet transmitting unit which transmits the first packet through an extra-device port of the second interface unit if said filtering execution decision unit decides non-execution of filtering or if said filtering result decision unit decides allowance of forwarding.

4 more elements

Dependencies are inferred from the claim text.